Mark Thomas searches for buried truths in Tanzania

Were more than 50 Tanzanian miners buried alive? The mine owners deny it, but local people claim the

Is Osama Bin Laden alive or not? All we know is that he has now released so many videos that he warrants his own section in HMV shops. His next one could even warrant a promotional tour. Obviously, there is a slim chance that the FBI and CIA might spot him. But it is only a slim chance. Conveniently, the latest video comes just as President George Bush is being heavily criticised for a lack of action on warnings given before the attacks on the World Trade Center.

If the release has been timed to distract public attention from the president's problems, it can't be a long-term strategy. Bin Laden doesn't have enough new video material to keep pace with Bush's cock-ups. Come the next major error by Bush, I bet Bin Laden will be down to releasing a workout video: "Declare jihad on your fat with Allah's Abdominiser and Osama!" Given Bush's propensity for blunders, it is doubtful we will get to the end of the year without seeing Osama's Out-takes: the bleeps and bloopers from his messages of death. It'll show all the mistakes the directors made while shooting the other videos - a sort of "it shouldn't happen to a terrorist" kind of thing. The mullahs will be sitting around listening to Bin Laden and, just as he gets to the heavy religious stuff, someone will pass wind.

But the question of how much the president knew is one that can also be asked of Bush Sr, albeit in a different circumstance. Bush Sr is on the board of Barrick Mining, a Canadian company that now finds itself embroiled in a row over allegations of a massacre (by another company) in Tanzania. These allegations have been brought to light mainly by the work of the Lawyers' Environmental Action Team in Tanzania and team members like Tundu Lissu. They have fought not only Barrick but the World Bank and their government to try to find out exactly what happened in a place called Bulyanhulu.

In 1996, Sutton Resources Ltd was the Canadian parent company to Kahama Mining Corporation Ltd, which purportedly owned the gold mine. It claimed the mining rights to an area south of Lake Victoria called Bulyanhulu. This puzzled tens of thousands of local inhabitants, as the area had not only been mined by local people since the mid-1970s, but, in accordance with Tanzanian law, it had been set aside by the government specifically for artisanal (self-employed) miners.

Bulyanhulu's miners won an injunction forbidding forced eviction in August 1996. What followed is in dispute. Some miners returned to the pits and occupied them. Sutton says that, in an effort to stop the mines being occupied, company bulldozers started to push earth into the pits to seal them. It is an action that union leaders, inhabitants and lawyers say resulted in more than 50 men being buried alive. Sutton denies this.

The public outcry in Tanzania was followed in 1999 by Barrick buying Kahama and the mine. Barrick, though nobody accuses it of being directly involved, also denies that there was a massacre, as does the World Bank, which backed the mine financially in 2000. Nobody seems willing to excavate the pits to see if the bodies are there or not. But the Multilateral Investment Guarantee Agency (Miga), which is part of the World Bank, provided Barrick with "political risk insurance" worth US$115.8m. So if something like a revolution or a general strike occurred, disrupting gold-mining, the banks backing Barrick would be covered.

The World Bank's guidelines say it will not support projects that involve forced evictions and which violate human rights. Miga claims to have investigated the incident, but many questions remain unanswered. Why did Miga approve the insurance when Barrick's own figures state that only 56 inhabitants out of tens of thousands received token compensation for the loss of habitat and livelihood? Did they notice and consider the legal implications of Kahama's mining licence, which does not mention Bulyanhulu at all, and states that it is for an area 150 miles away? And how can Miga ignore the growing number of people who testify that their loved ones died in those pits?

The UK's executive director on the board of Miga takes instructions from the Department for International Development. So what did Clare Short's department have to say about using public money to back the mine?

In March, an international fact-finding mission went to Tanzania and spoke to people who alleged they had lost loved ones in the mine shafts. But the mission was detained by the Tanzanian police and prevented from getting to Bulyanhulu to question all 250 people who wanted to testify. Tundu Lissu and Rugemeleza Nshala, the president of the lawyers' action team, have been charged with sedition for investigating the alleged massacre. The trial begins this month and, if convicted, the accused face up to two years in prison. Short should find a way to support people who are risking their freedom to find the truth.