Mohammed al-Askari said the arrest of al-Masri, also known as Abu Hamza al-Muhajir, was confirmed to him by the Iraqi commander of the province. There was no immediate confirmation or comment from U.S. forces on the arrest.
The U.S. military in Baghdad said "we are currently checking with Iraqi authorities to confirm the accuracy of this information."
Interior Ministry spokesman Maj. Gen. Abdul-Karim Khalaf said that Mosul police "arrested one of al-Qaida's leaders at midnight and during the primary investigations he admitted that he is Abu Hamza Al-Muhajir."
News of the arrest was also reported by Iraqi state television and Arab satellite TV stations.
The state channel, Iraqiya, said that Minister of Interior Jawad al-Bolani would reward Mosul police for the capture.
Interior Ministry spokesman Khalaf told the station by phone that a source close to the al-Qaida leader informed Mosul police that al-Masri would be at a house in the city's Wadi Hajar area at midnight Wednesday.
"The police raided this house and arrested him. During the primary investigation, he confessed that he is Abu Hamza Al-Muhajir, the leader of Al-Qaida in Iraq. Now a broader investigation of him is being conducted," he said to Iraqiya.
