Mining giant Glencore PLC has announced it agreed to a $960m (£766.2m) deal to acquire stakes in two African giant Congolese cobalt and copper mines owned by its controversial business partner, the Israeli billionaire Dan Gertler.

Swiss mining company Glencore said on 13 February it would acquire the 31% stake held in Mutanda Mining by Gertler's Fleurette Group – valued at $922m – and Gertler's minority holding in Katanga Mining Ltd – valued at $38m.

Under the deal, Glencore is set to control 100% of the Mutanda cobalt mine, and 86% of the copper mine in Katanga. But the deal will also distance the mining giant from the controversial Israeli billionaire, who became a partner a decade ago when the two entities both invested in DRC-focused mining company Nikanor PLC, which later merged with Katanga Mining Ltd.

A magnet for controversy, Gertler began operating as a diamond merchant in the DRC in the late 1990s.

Most recently, the United Kingdom Serious Fraud Office said it was investigating Gertler over mining deals in the DRC.

The Israeli is also at the centre of a US Department of Justice (DoJ)'s criminal case against a leading Wall Street hedge fund, Och-Ziff Capital Management LLC. The hedge fund, the DOJ alleges, had joint-control of African Global Capital (AGC), which it used to find lucrative business opportunities on the continent.

According to DoJ documents, one of AGC's partners in Congo, is referred to as "an Israeli businessman" with "significant interests in the diamond and mineral mining industries in the DRC". The DoJ claims that Gertler paid more than $100m in bribes in the DRC, including more than $10m to President Joseph Kabila, to facilitate mining deals.

Gertler, who amassed a fortune through the DRC's natural resources industry, has always denied any wrongdoings in his dealings in the region and has never been charged with a crime related to his activities.

Gertler's Fleurette Group also declined to comment when approached. "Mr Gertler has always made it clear that his business dealings in the DRC are entirely proper and appropriate. That remains the case. Beyond that, he is not able to comment on allegedly leaked documents," the company said in a statement.