Allegations against Minty were so serious that they should be probed by the department of international relations and the diplomat suspended during the probe, DA parliamentarian David Maynier said on Thursday.
MTN is alleged to have pressed Minty, South Africa's ambassador to the International Atomic Energy Agency in Vienna, to abstain during a crucial vote on the Iranian dossier at the UN nuclear watchdog in 2005.
The claim was made by Turkish rival mobile operator Turkcell in a court challenge to MTN's involvement in running a mobile phone operating licence in Iran.
Maynier said there was no proof that Minty had been swayed but the serious nature of the claims warranted an investigation.
The allegations, made by Turkcell in papers filed in a US court this week, led to the suspension of South Africa's former ambassador to Tehran, Yusuf Saloojee.
Turkcell claims that MTN made a payment of $200 000 towards the purchase of a house for Saloojee in South Africa.
Maynier said International Relations Minister Maite Nkoana-Mashabane was correct to suspend Saloojee while probing the allegations, and should now do the same with Minty.
"I will … [call] on her to suspend and probe Ambassador Abdul Minty for his alleged role in the scandal surrounding the MTN Group," he said.
"We must be absolutely sure that our foreign policy is not for sale and cannot be influenced by powerful companies such as the MTN Group [Ltd]."
The Hawks announced last month they were investigating claims that MTN had obtained its operating licence in the Islamic republic through corrupt means.
Though Turkcell successfully bid for the licence, it was finally awarded to MTN Irancell, a consortium in which MTN holds a 49% stake. MTN insists there was nothing untoward about the process, and that Turkcell lost out because it failed to comply with Iranian legal and commercial requirements. – Sapa