A letter written by a New York City police officer on his deathbed has implicated the department and the FBI in the assassination of Civil Rights leader Malcolm X.

In his letter, written on Jan. 25, 2011; NYPD officer Ray Wood admitted he “participated in actions that in hindsight were deplorable and detrimental to the advancement of my own Black people.”

Wood, who was working undercover on the day of Malcolm X’s assassination, claimed it was his job to “infiltrate Civil Rights organizations” and find evidence of criminal activity so that the FBI could arrest its leaders.

These arrests included two of Malcolm X’s “key” security guards, who were arrested days before his assassination in a plot to bomb the Statue of Liberty. The arrests of the guards meant that Malcolm X had no security detail at the entrance of the Audubon Ballroom on Feb. 21, 1965; when he was fatally shot.

“It was my assignment to draw the two men into a felonious federal crime, so that they could be arrested by the FBI and kept away from managing Malcolm X’s door security on Feb. 21, 1965,” Wood wrote in his letter. “… At that time, I was not aware that Malcolm X was the target.”

Wood added that his “actions on behalf of the New York City Police Department were done under duress and fear” and said he could have faced “detrimental consequences” if he did not follow orders.

“After witnessing repeated brutality at the hands of my coworkers (Police), I tried to resign,” he wrote. “Instead, I was threatened with arrest by pinning marijuana and alcohol trafficking charges on me if I did not follow through with the assignments.”

Years later when his health was failing, Wood wrote the confessional letter to help exonerate Thomas Johnson, one of the men convicted of killing Malcolm X. Johnson was arrested the night of Malcolm X’s assassination for protecting Wood’s cover and “the secrets of the FBI and NYPD,” he wrote.

Wood only wanted his letter to be revealed to the public after his death, his cousin Reginald Wood Jr. said. The letter was read by Reginald in a press conference on Saturday (Feb. 20).

“It is my hope that this information is received with the understanding that I have carried these secrets with a heavy heart and remorsefully regret my participation in this matter,” the letter read.

On “Good Morning America,” Reginald described his cousin as a “good man that was tricked and forced to betray his own people.”

In light of the new accusations, Malcolm X’s three daughters, Wood’s family and Civil Rights attorney Benjamin Crump have demanded the investigation into the assassination be re-opened immediately.

“Any evidence that provides greater insight into the truth behind that terrible tragedy should be thoroughly investigated,” Ilyasah Shabazz, Malcolm X’s daughter, said.

In a statement to ABC News, the Manhattan District Attorney’s office said, “Our office’s review of this matter is active and ongoing.”

The NYPD added that it has “provided all available records relevant to that case to the District Attorney. The department remains committed to assist with that review in any way.”

The FBI did not issue a response to the claims.