Iraq has canceled a $4.2 billion weapons deal with Russia.

A spokesman for Prime Minister Nouri al-Maliki announced the cancellation Saturday, saying the prime minister had “suspicions of corruption” surrounding the deal.

The spokesman said an investigation in under way, but it was not immediately clear who or what was being investigated.

Baghdad and Moscow signed off on the weapons package in October. The deal would have made Russia Iraq's biggest arms supplier after the U.S.

Reports say 30 Mi-28 attack helicopters were to be included in the weapons package.

Russia has not commented on the cancellation. Moscow was the main supplier of arms to Iraq under Saddam Hussein.