A former Rwandan official appeared in a London court on Tuesday charged with encouraging the massacre of Tutsis and ordering six killings in the first week of the 1994 Rwandan genocide.

Vincent Brown, formerly known as Vincent Bajinya, is the first person to be charged in Britain over the genocide, in which more than 800 000 Tutsis and moderate Hutus were killed in 100 days in massacres orchestrated by the Hutu ruling majority.

He is charged with one offence of conduct ancillary to genocide in Rwanda's capital Kigali between April 6 and 13, 1994 — the first week of the genocide, after Rwanda's President Juvenal Habyarimana was killed alongside Burundi's President Cyprien Ntaryamira in a missile attack on their plane.

Brown also faces six offences of conduct ancillary to murder as a crime against humanity, alleging he ordered six killings in four days, including that of a young mother and her baby son.

The 65-year-old appeared at Westminster Magistrates' Court, where prosecutor Jane Stansfield said Brown was head of the Department of Family Health within Rwanda's National Office of Population when the genocide began.

Stansfield said Brown was alleged by witnesses, including his neighbours, to have been "the leader and supervisor of physical acts of violence which were carried out by others".

Brown, who has lived in Britain for more than two decades, denies involvement in the genocide and says he left Kigali in mid-April 1994, with his family leaving Rwanda that July.

His lawyer, Sam Blom-Cooper, said Brown welcomed being charged as an opportunity to clear his name.

"These are appalling crimes, terrible murders that were committed back in 1994," he said. "But this, finally, does represent the beginning of the end for Dr Brown."

Judge Paul Goldspring said he would grant Brown bail ahead of his next court appearance at the Old Bailey on October 9, subject to him providing sufficient funds as a security.

British police's War Crimes Team said on Monday that six others remain under investigation, including two men arrested on suspicion of genocide and crimes against humanity.