A spokeswoman for Israeli President Shimon Peres says he categorically denies a report he offered nuclear warheads to South Africa in 1975, when he was Israel's defense minister.

Peres' spokeswoman, Ayelet Frisch, said on Monday that there were "never any negotiations" on this between the two countries, as reported by Britain's Guardian newspaper.

The report is based on an American academic's research and cites reportedly secret minutes of Peres' meeting with senior South African officials discussing the issue.

Frisch also says Peres was not contacted for comment before the article was released late Sunday.

Israel has never acknowledged or denied possessing nuclear weapons, though it is universally assumed to have them.