By Michael Georgy

DUBAI (Reuters) -Seif al-Adel, a former Egyptian special forces officer who is a high-ranking member of al Qaeda with a $10 million U.S. bounty on his head, is now the "uncontested" leader of the militant group, according to a new U.N. report on the organisation.

Al Qaeda has not formally named a successor for Ayman al-Zawahiri, who was believed to have been killed in a U.S. missile strike in Kabul last year, dealing a blow to the organisation since its founder Osama bin Laden was killed in 2011.

Although a U.S. intelligence official said in January that Zawahiri's succession remained unclear, the United Nations report assessing risks from the group said: "In discussions in November and December, many Member States took the view that Seif al-Adel is already operating as the de facto and uncontested leader of the group."

Zawahiri's death piled pressure on the group to choose a strategic leader who can carefully plan deadly operations and run a jihadi network, experts on al Qaeda say.

Unlike his slain predecessors who maintained a high profile with fiery videos broadcast around the globe threatening the United States, the experts say Adel planned attacks from the shadows as he helped turn al Qaeda into the world's deadliest militant group.

Adel was indicted and charged in November 1998 by a U.S. federal grand jury for his role in the bomb attacks on the U.S. embassies in Tanzania and Kenya that killed 224 civilians and wounded more than 5,000 others.

There are few photos of him, aside from three pictures - including a very serious black and white image of him on the FBI most wanted list.

Beyond the operations in Africa, his training camps and link to the killing of U.S. journalist Daniel Pearl in Pakistan in 2002, according to U.S. investigators, little else is known about Adel.

The U.S. State Department says Adel is based in Iran. The department’s Rewards for Justice programme is offering up to $10 million for information on Adel, whom it says is a member of "al Qaeda’s leadership council” and heads the organisation’s military committee.

A highly dangerous murderer agent to the free World !