A Tanzanian citizen is accusing the United States of America (USA) of not fulfilling a promise of 27 million dollars for helping to uncover the hideout of the leader of the Al-Qaeda terrorist group, Osama Bin Laden.

Osama Bin Laden is said to have led several terrorist attacks against US civilians and military personnel, including that of September 11, 2001. He was assassinated on May 2, 2011, in Abbottabad, Pakistan.

The Tanzanian, Jabaldin Hamis Ijengo, claims to have played an important role in locating Bin Laden. He allegedly provided "precious" information about the terrorist leader's whereabouts to the US embassy in Dar es Salaam in 2005.

The US did not reward him for his cooperation, and now he intends to sue the US.

"Unfortunately, failure to comply with this demand will leave me with no alternative but to go to court, which could mean initiating legal proceedings at your own risk, without prior warning," the informant warned the Tanzanian press.

The US embassy in Dar es Salaam, through its spokesperson Kalasha Holmes, refused to comment on the matter.

"While we cannot comment on ongoing law enforcement cases, all information provided to the Rewards for Justice program is reviewed and vetted by the appropriate U.S. authorities," Holmes wrote in an email.

The "informant" recalled that the US had promised a reward of 27 million dollars to anyone who helped uncover Bin Laden's whereabouts. The promise was also in response to the 1998 attacks on the embassies in Dar es Salaam and Nairobi.

"On the basis of this assurance, in October 2005 I provided crucial information to the US Embassy in Tanzania about Osama bin Laden's whereabouts in Pakistan. This information was received by the US Embassy's special agent, Ms. Brunn Anne."

The "informant" set a deadline of 21 days to receive the reward.

"I acted in good faith, risking my safety to help apprehend the terrorist, in the expectation that the promised reward would be fulfilled," he said in a letter.