Image copyright AP Image caption Claudia Lacy (centre): "I just knew automatically he didn't do that to himself"

The FBI is investigating the hanging death of a black teenager in North Carolina previously ruled a suicide.

Lennon Lacy, 17, was found hanging in a trailer park in Bladenboro, North Carolina, in August.

An FBI spokeswoman confirmed that the agency was reviewing the investigation into his death "at the request" of the local federal prosecutor.

The state medical examiner initially ruled it a suicide based on reports from the police and the county coroner.

Lacy's mother, Claudia, wrote an article in the UK Guardian newspaper in which she said the police failed to fully investigate her son's death, including not asking why he "was found with a pair of white sneakers on his feet that he didn't own and were two sizes too small for him".

His family and the North Carolina chapter of the National Association for the Advancement of Colored People (NAACP) has called for a federal investigation into his death and is holding a rally on Saturday.

The Reverend William Barber, president of the NAACP chapter told the Associated Press that many questions surrounding Lacy's death remain unanswered, including why he was found hanging from a belt he did not own.

"We don't know what happened that terrible night," Rev Barber said.

A spokeswoman for the State Bureau of Investigation said agents had addressed all viable leads and a district attorney had previously said he had seen no evidence of foul play.

Ms Lacy told AP she could not believe her son killed himself.

"When I saw him, I just knew automatically he didn't do that to himself," she said on Monday.

"I know my child. As a mother, I would have sensed if something was wrong to the point that he was going to harm himself."