DUBAI, United Arab Emirates — The top Saudi in al-Qaida's Yemen-based wing has apparently released an audio message denying reports he was killed last month, a group that monitors Islamist websites said on Monday.

In the audio posted on jihadist websites on Sunday, a man identified as Said al-Shehri said reports of his death were fabricated and aimed to cover up the killing of civilians by U.S. drones, the U.S.-based SITE Intelligence Group said.

"The news that was reported about my killing in the Arabian Peninsula is a rumor to cover up the killing of the innocent, unarmed Muslims in Yemen, who were killed by American drones in the east and west," said the man claiming to be Shehri.

Shehri, who was freed by U.S. authorities from detention at Guantanamo Bay, Cuba  — only to become second-in-command of Al-Qaida in the Arabian Peninsula (AQAP) — has been reported killed before only to emerge unscathed.

Yemen's Prime Minister Mohammed Basindwa's media adviser Rajeh Bady told Reuters on Monday the audio "seemed authentic."

"From start we had doubts that Shehri was killed and we became sure later on that he was still alive," Bady said.

On September 16, Saudi Arabia's Interior Minister Prince Ahmed said that kingdom could not confirm the death of Shehri, according to pan-Arab Asharq al-Awsat newspaper.

The Yemeni Ministry of Defense website said on September 10 that Shehri and six other militants were killed during a Yemeni army operation in the remote Hadramout province in eastern Yemen. It gave no further details.

But a Yemeni security source had said Shehri was killed in Hadramout by a U.S. drone, rather than by the Yemeni military. U.S. officials declined to comment on the drone strike report.

U.S. officials described Shehri as one of the most important al-Qaida-linked militants to be released from Guantanamo Bay detention facility, where he was taken in January 2002 after being handed over by Pakistan to U.S. authorities.

A former officer in Saudi Arabia's internal security force, Shehri allegedly joined al-Qaida and helped Saudi militants travel to Afghanistan via Iran, according to a classified Pentagon report made public by WikiLeaks.

Shehri was released to Saudi Arabia in 2007 and put through a Saudi rehabilitation program for militants. He later returned to the battlefield in Yemen and became AQAP's number two. Shehri was wanted by Yemen for a suspected role in a U.S. Embassy attack in 2008.