The filmmakers provided the materials to The New York Times, and offered a reporting collaboration. The Times investigated the claims but did not enter into such a partnership. When asked about the discrepancies in Mr. Jones’s story, the filmmakers acknowledged that they could not corroborate the account and that the plan Mr. Jones had described might not have been medically possible. They encouraged journalists to investigate further.

“Journalists reporting on it should take care to contextualize the allegations,” said one of the filmmakers, the Danish producer Peter Engel, “and to remind readers that, even if proven true, there is no reason to turn away from modern medical clinics, which are regulated in ways which did not exist in the 1980s at the end of the apartheid era.”

Such a cautionary note was not included in the version of the film seen by The Times.

The documentary adds new details and raises fresh questions about the death of Mr. Hammarskjold, a Swedish diplomat whose plane crash has never been fully explained. A United Nations panel concluded that there was “persuasive evidence that the aircraft was subjected to some form of attack or threat.”

But the AIDS accusations are likely to generate the most attention. And though Mr. Jones’s account cannot be corroborated, there is support for the notion that the militia was at least interested in AIDS research. One young woman, Dagmar Feil, was killed in front of her home in 1990. Her mother told the South African authorities that she had been conducting AIDS research for the militia at the time, according to contemporaneous documents.

Much is unknown about the militia, and it is difficult to sort fact from fiction. Its leader, Keith Maxwell, had claimed that it was rooted in British admiralty traditions and traced its lineage to the early 1800s. When the Hammarskjold documents surfaced in the late 1990s, government officials and experts puzzled over what to make of them. Many dismissed them as forgeries or the product of a Soviet disinformation campaign.

Whatever the group was in that era, by the 1980s and early 1990s it appeared to be a mercenary organization. Paramilitary groups and private military organizations were common during the apartheid era, and the group known as Saimar (pronounced “Sy-marr”) advertised for military-trained men to serve in unspecified foreign operations.

Mr. Maxwell, who reportedly died in 2006, also ran medical clinics of some kind in South Africa, though he was not a doctor. And he claimed publicly that AIDS would ultimately be good for humanity and would decimate the black population in South Africa.