NEW YORK -- A police watchdog agency investigator who leaked the disciplinary record of a white police officer involved in the chokehold death of unarmed black man Eric Garner resigned on Thursday.

The investigator, who was not publicly identified, worked for the Civilian Complaint Review Board for less than a year and had no role in the investigation of any of the disciplinary cases against Officer Daniel Pantaleo that were leaked to the website Thinkprogress.org, the board said.

"After a swift and thorough internal investigation, the Civilian Complaint Review Board identified the employee who was the source of the leak," board secretary Jerika Richardson said. "As of today, that individual no longer works at CCRB."

The agency investigates claims of police misconduct, substantiates complaints and offers disciplinary suggestions like retraining or loss of vacation days to the New York Police Department, the nation's biggest police department. The police commissioner decides whether to discipline an officer.

Pantaleo's record was published on the website this week. It included eight disciplinary cases of abuse and excessive force, four of which were substantiated. The officer was disciplined in two of the cases. Police personnel records are not public information under state law.

Garner, who was accused of selling loose, untaxed cigarettes, was stopped by police in 2014 and refused to be handcuffed. Pantaleo is seen on a bystander's cellphone video putting Garner in an apparent chokehold, which is banned under NYPD policy.

The heavyset Garner, who had asthma, is heard gasping, "I can't breathe." He later was pronounced dead at a hospital.

Garner's death sparked angry protests from people complaining about the treatment of black men and boys at the hands of white police officers.

The medical examiner ruled Garner's death a homicide caused in part by the chokehold. But police union officials and Pantaleo's lawyer argued the officer used a takedown move taught by the police department, not a chokehold, and said Garner's poor health was the main reason he died.

A grand jury refused to indict Pantaleo in Garner's death. A federal civil rights probe is in limbo.

The head of Pantaleo's union, Patrick Lynch, said the resignation of the watchdog investigator was a good first step.

"But the release of a police officer's confidential personnel records is still a crime that should be thoroughly investigated and, if necessary, prosecuted to the fullest extent of the law," he said.

The investigation by the Civilian Complaint Review Board was internal and didn't involve the NYPD. Police department officials said they would investigate.