Lawyers for Vanessa Perroncel, the former mistress of England footballer John Terry, believe that one of her telephone calls may have been bugged and a mobile phone company has said that an attempt has been made to intercept the voicemail messages of one of her friends.
It has also emerged that Perroncel has filed writs for breach of privacy against News Group Newspapers (which publishes the Sun and News of the World) and against Mirror Group Newspapers. They relate to stories about her relationships, family life and about medical and health matters.
Press Gazette understands that legal negotiations are ongoing with other news organisations. The Information Commissioner's Office has confirmed that it is investigating this new phone-hack claim.
A spokesman said: "This incident has been reported to us and we are looking into it, together with Vodafone, to establish whether any offences under the Data Protection Act have taken place.
"The Data Protection Act, which is regulated and enforced by the ICO, covers the processing of personal information. The interception of communications is covered by the Regulation of Investigatory Powers Act, which is separate to the Data Protection Act and is not regulated by the ICO."
In January, the News of the World overturned a far-reaching privacy injunction brought by John Terry to reveal that he had a four-month affair with Perroncel. The judge in the case ruled that knowledge of the affair was already widely circulated in the football industry and that an injunction was inappropriate because Terry was more concerned about protecting his business interests.
Perroncel then engaged the services of publicist Max Clifford who said that she had been offered £250,000 by the media to tell her side of the story. On Friday, 5 February, Perroncel issued a statement saying that she had decided not to talk to the press about her private life. The following Sunday the News of the World reported that a "deal had been done" with John Terry to buy her silence.
But speaking to the media for the first time, Perroncel told the Guardian's Nick Davies that she had not been paid a penny by Terry. This point was reiterated to Press Gazette by Perroncel's lawyer.
Explaining Perroncel's decision to sue for breach of privacy, Charlotte Harris of JMW Solicitors, said: "Vanessa is taking legal action as a last resort because the newspapers simply did not stop publishing private, untrue and deeply insulting information about her."
She said that Perroncel had opted to go down the legal route, rather than going to the Press Complaints Commission, because she thought it would be more effective. No legal action has yet been taken over the new phone hacking allegation, Harris said, because it was at the very early stages of investigation.
But she said she was confident the perpetrator would be identified and she said that once this happened, further legal action for breach of privacy would be taken. Perroncel's best friend and confidante Antonia Graham has been told by Vodafone that an attempt was made to intercept her voicemail.
According to Harris, suspicions were further raised after the exact wording of a private telephone conversation between the pair subsequently appeared in various media outlets. Press Gazette understands that the News of the World is not suspected of being involved in this latest phone-hacking allegation.
In her Guardian interview, published on Saturday, Perroncel said that she had been hounded by tabloid journalists since the John Terry affair story broke.
She said: "It is horrible. It is like a nightmare. Every day you think: 'What else are they going to say about me?' It is so intrusive and so false. Every day so many lies - and then people making judgments because of the lies."
Dominic Ponsford is the editor of Press Gazette.