Human rights groups have asked Tanzania’s president on Wednesday to address allegations of rights abuses at Acacia Mining’s North Mara gold mine in talks under way with the firm’s parent company, according to a letter seen by Reuters.

In a letter to President John Magufuli, seven organisations have urged him to ensure longstanding accusations of human rights violations at the gold mine were given top priority in the talks.

Acacia is 63.9% owned by Barrick Gold Corp, the world’s largest gold miner by production.

Anneke Van Woudenberg, executive director of U.K.-based Rights and Accountability in Development, one of the groups that signed the letter, said it would be “scandalous” if longstanding rights violations were not resolved in the talks.

Tanzania and Barrick announced a deal last week under which Acacia would pay $300 million and grant a 16 percent stake in its mines to the East African country.

Tanzania and Barrick had launched talks in July after Tanzania accused Acacia of evading taxes by under-declaring exports – allegations Acacia denied.

“The troubling human rights record at Acacia’s North Mara mine has been well-known for years,” Van Woudenberg said in a statement.

“If the Tanzanian government is going to take a stake in the mine it should ensure the abuses end and victims are granted adequate compensation and justice.”

Tanzanian government officials were not immediately available for comment on the letter. Acacia Mining and Barrick declined to comment.

Barrick and Acacia have previously denied the allegations of rights abuses, but acknowledged some incidents of violence at the mine caused by illegal miners.

The rights groups, both Tanzanian and foreign, urged Magufuli to order a judicial investigation into alleged unlawful use of force by police and mine security against alleged illegal miners.

According to the non-governmental organisations, which also include MiningWatch Canada and CORE Coalition, a British civil society network on corporate accountability, there have been at least 32 deaths of so-called “intruders” at the mine since 2014 and dozens of serious injuries.

The rights activists said a genuine partnership between Acacia and Tanzania was “hard to envision” when Tanzanian “citizens continue to lose their lives,” at the mine.

Tanzanian security forces arrested at least 66 people in June after hundreds of villagers invaded North Mara gold mine.

In February 2015, Acacia, formerly known as African Barrick, settled out of court with Tanzanian villagers seeking compensation over fatal incidents at the North Mara mine, a law firm representing the claimants said.