Two men found guilty of the 1965 murder of civil rights leader Malcolm X are to have their convictions thrown out, the Manhattan district attorney's office said Wednesday.

Manhattan District Attorney Cyrus Vance will hold a press conference on Thursday to announce the exoneration of Muhammad A. Aziz and Khalil Islam, his office said.

"These men did not get the justice that they deserved," Vance said in an interview with The New York Times. "What we can do is acknowledge the error, the severity of the error."

The newspaper said a 22-month investigation conducted jointly by the Manhattan district attorney's office and lawyers for the two men found that prosecutors, the FBI and New York police withheld evidence that would likely have led to their acquittal.

Manhattan District Attorney Cyrus Vance is to announce the exoneration of two men convicted of the 1965 murder of Macolm X
Manhattan District Attorney Cyrus Vance is to announce the exoneration of two men convicted of the 1965 murder of Macolm X AFP / Bryan R. Smith

Aziz, 83, was released from prison in 1985. Islam was released in 1987 and died in 2009.

A third man, Mujahid Abdul Halim, 80, confessed to the murder and was released from prison in 2010. He claimed during their 1966 trial that the other two men were innocent.

All three were members of the Black nationalist group Nation of Islam, which Malcolm X had recently renounced.

Malcolm X was shot dead by three gunmen on February 21, 1965 as he prepared to deliver a speech in a Manhattan ballroom.