"When [Maliki] returned from his trip to Russia, he had some suspicions of corruption, so he decided to review the whole deal. ... There is an investigation going on, on this," spokesman Ali al-Masawi told Russia Today.
Earlier reports Saturday indicated the deal -- which would have made Russia Iraq's second-biggest arms supplier after the United States -- was canceled.
Maliki's critics had questioned the deal, noting that Iraq had already signed multiple arms deals with the United States, the BBC reported.
Iraq's acting defense minister signed the initial contracts this year for 30 Mi-28NE night/all-weather capable attack helicopters, and 50 Pantsir-S1 gun-missile short-range air defense systems, RIA Novosti reported.