MTN, has however, been issuing statements to clear its name against the allegations.

Iran is MTN's fastest-growing branch, with more than 34 million subscribers. MTN has a 49 percent share in Irancell, owned and controlled by Iran Electronic Development Co.

MTN President and CEO Sifiso Dabengwa said talks between MTN and Turkcell have broken down as a result of Turkcell's demands for damages and its threat to file a lawsuit in the U.S.

"Turkcell's threat to abuse the U.S. legal system to pressure and extort money from MTN will not succeed," said Dabengwa in a statement last week.

Dabengwa said that MTN was not the cause of Turkcell losing the license in Iran. He said Turkcell's own "failures to meet Iranian legal and commercial requirements" caused its exit from the license process.