Human rights campaigners are calling for a consumer boycott of Angolan diamonds, citing serious human rights abuses in the north-eastern region of the country where they are mined.

The report, whose backers include George Soros's Open Society Foundation and Portugal's Mário Soares Foundation, is likely to embarrass the Angolan government, which human-rights campaigners have already criticised for its stewardship of the country's oil wealth.