Paddy Costello never knew what brought his brilliant career to a sudden end in 1954. He was the rising star of New Zealand's diplomatic service, its most effective operator, and easily its best linguist, being fluent in nine or ten languages, including Russian and French. He was the first diplomat to see and understand the horrors of Auschwitz. He told the west that the Soviet Union had the atom bomb before it was announced, and was not believed. No charges were ever laid, but MI5 told his bosses they believed Paddy to be a Soviet spy. Britain's top spy writers now describe him as one of the most dangerous and effective of Anthony Blunt's Cambridge recruits, who made Peter and Helen Kroger's spying activities possible.
After Paddy's death, his son Mick Costello was a mover and shaker in trade union and left-wing circles in the 1970s and 1980s. He was certainly the best-known communist in Britain, probably the cleverest, and easily the party's best linguist. "He speaks fluent Russian," people used to say meaningfully. "He was brought up in Moscow." The Sun called him "the most dangerous man in Britain". The word on Fleet Street was that Mick was a Soviet spy.
It seemed somehow to confirm Mick's treachery that he was thought to be following in a family tradition. In 1981, Paddy was named as a spy by a writer close to MI5, Chapman Pincher, in Their Trade is Treachery, and again by MI5's official historian Professor Christopher Andrew in The Mitrokhin Archive. Andrew said he was "one of the KGB's top ten". But a new book, The Sixth Man, published this month in Costello's native New Zealand (but not in Britain), convincingly argues that Paddy was framed. He was exactly what he appeared to be, and nothing else. As for Mick, "I don't know anything about spying," he told me last month.
He once consulted a top QC about whether to sue a newspaper for saying he had recruited KGB agents in Britain. "I was told that the fact that it's untrue won't help. A jury would say that the Communist Party has relations with the Soviet Union, so to suggest that a CP member is linked with the KGB is not damaging to your reputation." I've always thought that being industrial editor of the Morning Star and then industrial organiser for the Communist Party does not sound like good cover for a KGB spy.
On the other hand, Mick, now 71, is tall, thin and argumentative, with a mind that seems to approach every question elliptically, a voice that sounds as though he gargles with gravel, and a strong head for drink. Fleet Street's finest used to mention this last as part of his espionage equipment: as they became garrulous, he grew silent, a thin smile just visible behind his habitual small cigar. The weakness of this theory is that Mick's companions seldom had any secrets worth hearing.
Paddy was rather similar, judging by The Sixth Man, a sensitive and enthralling biography by a distinguished New Zealand novelist. In 1932 the young Paddy came to Britain to take up a schol arship at Trinity College, Cambridge, where his contemporaries included Blunt, Kim Philby, Donald Maclean, Guy Burgess and the communist theoretician and recruiting sergeant James Klugmann. Half a century later, after Paddy's death, the former MI5 agent Peter Wright, author of Spycatcher, told Chapman Pincher that he recalled Blunt naming Paddy as one of his recruits. Blunt's confession named several people, some of whom were innocent. But Paddy was not one of them. Wright was a fantasist with a grudge, and he had been in MI5 when it engineered Paddy's dismissal from the New Zealand diplomatic service.
Philby and the others never joined the Communist Party of Great Britain, for obvious reasons. But Paddy joined it in 1935, partly under the influence of Bella Lerner, an East End girl of Jewish Ukrainian extraction, whom he met and married that year. An anonymous New Zealand security service briefing later called Paddy "a dedicated and ruthless communist, determined to outdo his Ukrainian Jewish wife in her intellectual toughness as a communist". Mick says: "This is rubbish. Ukrainian and Jewish had nothing to do with it - my mother's politics came from London's East End, where she was brought up." Paddy left within two years, though not before couriering money from the British CP to its Indian counterpart, but Bella remained a communist all her life.
In May 1940 he was teaching ancient history at the University College of the South-West of England, now Exeter University. One of his students, Hubert Fyrth, appeared at the Old Bailey charged with passing on information contrary to the Official Secrets Act. With invasion of Britain imminent, it sounded dreadful. Actually, it was trivial. The French government had banned circulation of the Daily Worker, the communist newspaper, among British troops. Fyrth had received the decree from his brother, a naval officer, and passed it to the Daily Worker.
The distressed student went to Costello for advice, and Costello tried to be comforting. That was all; but it was enough to get Costello fired, and another black mark appeared against his name in the security files.
After four years of war service, distinguished by bravery, imagination and reckless binge drinking, he was offered a remarkable posting for a man with no diplomatic experience: third secretary with the New Zealand legation in Moscow. "I'm afraid I'm a bit left-wing, sir," he said to Prime Minister Peter Fraser. "That's all right," said Fraser. "We can do with one or two communists in Moscow."
He was an instant star on the diplomatic circuit. Travel was restricted, but Costello travelled pretty well anywhere he pleased. Looking back, sleepy Anglo-Saxon diplomats started to think he must have special access, but the truth was that his charm, deviousness and fluent Russian were generally enough to overcome bureaucratic obstacles. McNeish says he was not really a diplomat but "an inspired and intensely curious sport". He was also instinctively cosmopolitan, and the British Establishment distrusts such people. It is no accident that in the 1930s, the word "cosmopolitan" became code for "Jew" in upper-class anti-Semitic circles.
British security folk were furiously whispering in the ears of their New Zealand counterparts. Had he not once been a communist? Was his wife not a communist? And what about the Fyrth affair, in which "there is no proof that Costello was implicated in the disclosure of military information, but . . ." That "but" is the insinuating weapon of security files, silent and deadly.
Perhaps Moscow sealed his son's fate. Paddy, characteristically, did not want to send Mick to the international school, as most diplomats did, but to an ordinary school in Moscow where he would learn about the country and become fluent in its language. "I was there from the ages of nine to 14 - these are very important years," says Mick. "There was a great aura of triumph over the fascists."
But 1954 found Costello in what turned out to be his last diplomatic posting, Paris. The Paris legation, having seen the correct supporting documents, issued New Zealand passports for a New Zealander and his Canadian wife. The documents were forged, however, and the couple - Peter and Helen Kroger - used them to enter Britain, where they became the nerve centre of the Portland spy ring.
Today's spy writers suggest this was Paddy's contribution to the Krogers' activities. In fact, the legation seems to have followed the proper procedures. But what McNeish unearths is startling. Paddy didn't even issue the passports. It was done, in his absence, by a colleague.
It did not matter. The British had their knife in him, and that year they managed, after years of private insinuations, to persuade a new Conservative government in New Zealand to fire him. He never knew why.
Paddy was lucky. After a few months of un employment, his academic record won him an unexpected job as professor of Russian at Manchester University.
There, in 1956, his son Mick, a student at the university and president of its student union (he beat Anna Ford to the job) joined the Communist Party. That was the year everyone else was leaving it because of Hungary, and it is somehow typical of the Costellos, who clearly felt thoroughly uncomfortable if ever, by some mischance, they found themselves swimming with the current. Equally typically, after 20 years outside it since the break-up of Britain's Communist Party, Mick joined its intellectual successor, the Communist Party of Britain, this year.
"In 1956, Paddy didn't try to enforce his views on me, but he was very critical of the CP," says Mick. "I told him it was too late for him to criticise policies of which he had been a part and I had not. These were difficult conversations."
Paddy died in 1964. The Costellos, père et fils, would have been useless spies. But they were perfect suspects: clever and unable to disguise it, multilingual, unconventional and outsiders - the sort of person the public school club that was MI5 liked to fix on. MI5 rather despised spies, for a typically elliptical reason. Blunt and his recruits, says Mick, "found a way of engaging in their politics without changing the lifestyle they liked. They didn't have what it takes to stand outside a railway station, come rain or shine, selling the Daily Worker."
"The Sixth Man: the Extraordinary Life of Paddy Costello" by James McNeish is published by Vintage New Zealand (NZ$35)
Spies by numbers
First man Donald Maclean – British diplomat who gave Soviets information about atomic weapons
Second man Guy Burgess – transmitted secret documents to the Soviets while working for the BBC and Foreign Office
Third man Kim Philby – head of Soviet counter-espionage at MI6 while working as a Soviet spy
Fourth man Anthony Blunt – MI5 agent who passed intelligence from decrypted Enigma messages to the Soviets
Fifth man James Klugmann – close friend of Burgess, Maclean and Blunt, he was widely suspected
Research by Alyssa McDonald