Tanzanian police have killed 65 people and injured 270 during years of sporadic clashes with villagers at a controversial Canadian-owned gold mine, according to evidence heard by a Tanzanian government inquiry.

The alleged number of fatalities, based on complaints given to the inquiry by local communities, is the first official estimate of the scale of reported violence at the North Mara gold mine, operated by the African subsidiary of Barrick Gold Corp.

The Toronto-based company has faced criticism for many years for the large number of violent deaths at the Tanzanian mine, where the mine has agreements with local police to provide security. Villagers routinely enter the site in search of low-grade rock, from which they can extract small bits of gold. They often clash with the police, who are accused of barring some villagers while accepting bribes from others to let them enter.

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Barrick's majority-owned subsidiary, formerly known as African Barrick Gold and now known as Acacia Mining, is based in London. It operates three major gold mines in Tanzania.

In July, in its interim results for the first half of this year, Acacia disclosed that the Tanzanian Mines Minister had appointed a commission to investigate the disputes between the North Mara mine and the local communities.

The mining company praised the commission's report, which has been shown to local communities near North Mara. The company called it "a fair outcome for all stakeholders" but did not mention the number of fatalities and injuries that were cited in the report.

In the Swahili-language report, obtained by The Globe and Mail, the commission said it had received complaints of 335 cases of abuse by Tanzanian police, including 65 deaths and 270 injuries. The complaints were given to the commission in February and March when it visited the remote region where the mine is located.

The report did not give the time period for these deaths and injuries, but the numbers appeared to date back to 2006, when Barrick acquired the North Mara mine.

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In a separate confidential letter obtained by The Globe and Mail, a senior Tanzanian official told the company that the government is worried by the fatalities at North Mara, the "escalating" number of intrusions by villagers, and the reported collusion between the police and some of the trespassing villagers.

"The government cannot allow this situation to continue," said the letter, sent to a vice-president of African Barrick Gold in November, 2014, by Eliakim Maswi, the permanent secretary of Tanzania's Energy and Minerals Ministry.

He said the situation calls for "urgent action" from the government and other involved parties to reduce the clashes and the fatalities and injuries among the intruders and police. The intrusions were escalating, despite the presence of about 160 police at the mine site, the letter said.

Two independent activist groups, Ottawa-based MiningWatch Canada and a British group known as Rights and Accountability in Development (RAID), visited the mine site in July and August. They said the actual number of fatalities at the mine site might be much greater than the commission reported. Citing reports from opposition sources and human-rights monitors, they said there could have been more than 300 violent deaths at North Mara since 1999, including the deaths of women and children who were not trespassing on the mine site.

They alleged that hospital records and postmortem reports have sometimes been falsified to conceal the extent of the mine-related deaths and injuries. And they said their own investigation has found 22 cases of alleged unlawful killings by police or mine security personnel at the site, mostly since 2014.

"It is incomprehensible and deeply concerning that any corporation would tolerate such levels of abuse in pursuit of profit," said a statement by Catherine Coumans of MiningWatch Canada.

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Giles Blackham, investor relations manager for Acacia, declined to give any estimate of police-related deaths at the mine site since the company's acquisition of the mine in 2006. But he said the fatalities have been "sharply decreasing" in the past three years, and only two such deaths have been recorded this year.

The commission of inquiry at North Mara "listened to uncorroborated complaints regarding police-related fatalities and injuries" and did not try to validate the complaints, Mr. Blackham said in response to questions from The Globe.

He said the company has reduced the violent clashes at North Mara by building perimeter walls around the mining areas, bringing in a specialist security contractor, improving its relations with the local communities and going underground at one of its pits to reduce the mine's footprint and lessen its impact on the villages.

The number of intruders at the North Mara mining areas has been reduced by 99 per cent since 2011, and there has been an average of fewer than 10 intruders a month in the active mining areas this year, Mr. Blackham said.

Editor's note: A previous version of this article incorrectly said there were three categories of complaints including 355 cases of torture or other abuse by the police, 65 fatalities caused by the police and 270 injuries inflicted by the police. In fact, the commission said it received complaints of 335 cases of abuse by Tanzanian police including these two categories: 65 deaths and 270 injuries.