JOHANNESBURG, MAY 31 -- Ronald Watson, a member of a well-known family of antiapartheid campaigners, has charged that a gunman who said he was working for South African authorities tried to assassinate him in the neighboring black state of Botswana.

Speaking by telephone this weekend, Watson said he managed to overpower and disarm the gunman, who had fired two shots at him.

The gunman has appeared in court in Botswana, where he gave his name as Steven Burnett and described himself as a British intelligence agent working for the South African security services.

He told chief magistrate Gabriel Rwelengera that he had been sent to Botswana by the South African authorities to kill Watson, whom he described as an activist of the underground African National Congress. Burnett was charged with attempted murder.

The South African police have declined to comment, describing the allegation as "completely a security matter."

A spokesman for the British Embassy in Botswana confirmed that Burnett was a British citizen and said he visited Botswana frequently from South Africa, where he had lived since 1982.

Watson and his three brothers have been at the center of a political controversy in South Africa since they quit their whites-only rugby club to join a black club in the racially conservative city of Port Elizabeth 12 years ago.

Despite open hostility by other whites, and what they call a campaign of harassment by the police, the brothers have identified closely with the local black community, which regards them as heroes.

In the telephone interview from Gaborone, where he said he was hiding because he feared another attempt on his life, Watson said he believed the South African security police had set out first to isolate the brothers, then to discredit them and were now prepared to eliminate them because of their continued campaigning against apartheid.