In a Friday statement, Africa's biggest mobile-phone operator MTN Group Ltd. (MTN) said that an internal investigation, into the procedure which the company had followed for obtaining a wireless-service license in Iran back in 2005, has revealed that it had not violated any laws to secure the license.

The disclosure by MTN - that its Iran deal was legitimate - comes in the wake of the allegations which its rival Turkish mobile phone operator Turkcell Iletisim Hizmetleri AS had leveled against it, claiming that MTN had obtained the license by bribing South African and Iranian officials.

Turkcell was competing with MTN for securing the same license, to jointly run a mobile phone firm in Iran; but the deal was finally struck by MTN.

With MTN having secured the license, Turkcell filed a case against MTN in a US court, seeking $4.2 billion in damages. About its decision to file the case in a US court, Turkcell said that the decision was based on the fact that MTN had violated "rules of international law."

Meanwhile, about the results of the internal investigation, MTN said in the statement that a team of company-appointed investigators, under the leadership of former UK House of Lords Judge Leonard Hoffmann, had reached the conclusion that there was no evidence of bribes or promises which MTN had allegedly made for securing the South African government's support for Iran's nuclear policy at the International Atomic Energy Agency.