Baghdad: A man seized by Iraqi forces in the northern city of Mosul is not Al Qaida's leader in Iraq Abu Ayyub Al Masri, a senior US military official said on Friday.

"He has not been detained," the official said.

Several Iraqi officials had earlier said Al Masri, also known as Abu Hamza Al Muhajir, had been captured in an operation late on Wednesday.

Al Masri was a close associate of Al Qaida deputy leader Abu Musab Al Zarqawi, and has a US bounty of $5 million on his head.