GUANTÁNAMO BAY, Cuba — The United States government on Thursday offered a $4 million reward for information on the whereabouts of a Sudanese man who was convicted of war crimes at Guantánamo, was repatriated in 2012 and is suspected of recruiting for Al Qaeda’s branch in Yemen.

It is believed to be the first case of the United States offering a reward for the whereabouts of a prisoner released from Guantánamo by the Obama administration.

The announcement by the State Department of the new bounty on Thursday offered up to $4 million for information on the location of the Sudanese man, Ibrahim al-Qosi, 59. He pleaded guilty at Guantánamo in 2010 to providing support for terrorism and Al Qaeda in exchange for his repatriation. The reward announcement described Mr. al-Qosi as a member of the leadership team of the Yemen-based Al Qaeda in the Arabian Peninsula.

Mr. al-Qosi also said he fired a mortar for a militia helping the Taliban fight the Northern Alliance but said he was not involved with and did not know in advance about the Sept. 11 terrorist attacks. He was captured in Pakistan in 2001 and was among the first detainees brought to Guantánamo, as a suspected Bin Laden bodyguard.

Three years after his repatriation, Mr. al-Qosi began appearing in videos and other publications of Al Qaeda in the Arabian Peninsula and, according to the State Department, “has encouraged lone-wolf attacks against the United States in online propaganda.”

Guantánamo today has 40 prisoners, including nine who have been convicted or face charges in the military commissions. The Bush administration released about 540 of the approximately 780 detainees it brought to Guantánamo starting in January 2002. The Obama administration transferred about 200 more.