LUSAKA, Zambia — A Briton in custody in Zambia in connection with the London bombings told investigators he was once a bodyguard for al-Qaida chief Osama bin Laden, officials said yesterday.

Authorities have been questioning Haroon Rashid Aswat about 20 phone calls he allegedly made to some of the July 7 bombers, said the Zambian officials, who spoke on condition of anonymity because they were not authorized to speak to the media. The bombings killed 56 people, including the four bombers.

The Zambian officials said intelligence agents followed Aswat to Lusaka after he entered the country last week from Botswana and arrested him at a house in the capital.

London's Metropolitan Police declined to comment.

Before he was detained in Zambia, the officials said, Aswat had been hiding in Johannesburg, South Africa.

South African officials declined to comment yesterday on media reports that Aswat was under surveillance in South Africa and that authorities there did not act on an American request to arrest him after British security forces asked them not to.

U.S. officials in southern Africa declined to comment on the reports.

Aswat has been implicated in a 1999 plot to establish a terrorist training camp near Bly, Ore.

He reportedly was once an associate of Abu Hamza al-Masri, a radical Muslim preacher who is awaiting trial in Britain on charges of incitement to murder. Al-Masri also is wanted in the United States on charges of trying to establish the training camp in Oregon, involvement in hostage-taking in Yemen and funding terror training in Afghanistan.

Federal prosecutors in Seattle wanted to bring criminal charges against Aswat in 2002, but higher-level officials in the Justice Department blocked that effort, according to current and former federal law-enforcement officials.

The Justice Department wanted the case to be handled by the U.S. Attorney's Office in New York, which since the Sept. 11, 2001, attacks was set up to handle major cases of international terrorism, according to the sources.

Information from Seattle Times archives is included in this report.