Japan is trying to confirm whether Iraqi authorities detained someone carrying an ID card of a Japanese security worker believed to have been taken hostage and executed in Iraq, the Japanese Embassy in Baghdad said Thursday.

The security company that hired Akihiko Saito told the Japanese Embassy in London of secondhand information that Iraqi television reported an arrested militant holds Saito's ID, according to Japanese diplomatic sources.

The sources said, however, that apparently no Hart Security Ltd. officials have seen the television report and there are no other sources of information.

Iraqi TV aired the image of Saito's ID when it reported Wednesday on a defendant in the 2004 execution in Iraq of another Japanese captive, Shosei Koda, prompting the possibility that information on the report has been erroneously conveyed to the security firm.

Officials at the embassy in Baghdad said they have received no response from Iraq.

Saito has been missing in Iraq since May 8. A militant group said the next day it captured Saito after ambushing a convoy of 17 people, including him, near Hit, western Iraq.

The Sunni militant group, the Ansar al-Sunnah Army, later claimed in a video that Saito died after the group ambushed the convoy he was in.

The Ansar al-Sunnah Army posted on its Web site an image of a man lying face up on a concrete floor with his mouth open, blood near his mouth and hand, and his limbs spread out, as well as footage of Saito's passport and ID card in a four-minute video.