The Iranian Foreign Ministry said it is determined to continue its investigations into the U.S. move to kidnap an Iranian scholar, the local satellite press TV reported on Wednesday.

An image grab taken from Iran's state-run English-language Press TV shows Iranian nuclear scientist Shahram Amiri. [Xinhua/Reuters Photo]

Iranian Foreign Ministry spokesman Ramin Mehmanparast said that the ministry will move ahead with its investigations into Shahram Amiri's abduction by the U.S. intelligence service Central Intelligence Agency (CIA) agents in Saudi Arabia and into Washington's responsibility for the kidnapping through various legal and diplomatic means.

Iranian nuclear scientist Shahram Amiri, who Tehran claimed was kidnapped by the United States intelligence agents during pilgrimage to Mecca in Saudi Arabia in June 2009, "left the U.S. soil for Iran hours ago (on Wednesday) with the help of the Iranian government and the effective cooperation of the Pakistani embassy in the United States," Mehmanparast was quoted as saying.

Amiri emerged on Tuesday in the Pakistani embassy in Washington where he was taking refuge and demanded to immediately return to Iran, Press TV reported.

The Pakistani embassy represents the Iranian interest section, as Iran and the United States currently have no diplomatic relations.

In his exclusive interview with Press TV on Tuesday, Amiri said he was snatched by a group of unknown people and made unconscious before he found himself on an American plane heading for the United States.

According to two videos and one audio message featuring the nuclear scientist obtained by Iran's intelligence sources, Iran believed that Amiri was abducted by the U.S. Central Intelligence Agency (CIA).

Although the two videos contradicted with each other regarding the reason of his missing, Amiri's latest audio message revealed that he was offered 10 million U.S. dollars to appear on CNN and announce that he has willingly defected to the U.S..

Iran has urged the swift and unconditional release of the scientist.