The New York Times said the cellphone belonged to bin Laden's trusted courier, the man who unwittingly led U.S. intelligence to the terrorist leader. Bin Laden was killed May 2 during a Navy SEALs raid of his compound.
According to the report, senior American officials said the discovery indicates bin Laden used the group, Harakat-ul-Mujahedeen, as part of his support network inside Pakistan.
If true, the report raises questions about whether the militant group helped shelter and support the al Qaeda leader on behalf of Pakistan's spy agency.
Beyond providing leads about why bin Laden was able to live comfortably for years in Abbottabad, a town dominated by the Pakistani military just 35 miles from the capital city of Islamabad, the discovery also may help shed light on bin Laden's secret odyssey after he slipped away from U.S. forces in the Tora Bora region of Afghanistan nearly 10 years ago.
The Associated Press contributed to this story