The charges were made by Turkish rival Turkcell in a lawsuit filed in a US court last month as Turkcell accused MTN of using corrupt practices to win a contract with Irancell.

Turkcell claims it had already won the deal through an international tender, but that its license arrangement was suddenly dropped in favour of MTN.

A statement issued by MTN chief executive Sifiso Dabengwa said that “MTN did not cause Turkcell to lose ‘its’ licence in Iran.

“The Turkcell consortium was never awarded the licence in Iran,” Dabengwa said.

“It was Turkcell’s own failures to meet Iranian legal and commercial requirements that caused its exit from the licence process.”

Turkcell accuses MTN of bribing government officials and pressing Pretoria to offer Iran weapons and support for its nuclear programme in exchange for rights to the GSM licence.

“The allegation that MTN influenced South African foreign policy with regard to its armaments and nuclear position is simply ludicrous and has already been dismissed by the South African government,” Dabengwa said.

MTN now owns a 49-percent stake in Irancell, which holds the operating licence. MTN’s 33 million clients in Iran make up 21 percent of its total subscriber base.

The Turkcell dispute comes as Washington is pressuring allies to cut business ties with Tehran.