A 22-year-old man who stopped breathing while in police custody after his arrest during the June 18 Boston Celtics NBA championship celebration died yesterday, prompting an investigation by Boston police and the Suffolk County District Attorney's office into his death.

The parents of David Woodman, a former Emmanuel College student who was living in Brookline, said their son did not receive prompt medical attention while lying unconscious, face down on Brookline Avenue with his hands cuffed behind his back. They also accused police of failing to give them a full account of what happened.

Boston police say they immediately administered cardio-pulmonary resuscitation, flagged an ambulance after noticing Woodman was in distress, and did everything they could to help him before he was taken to Beth Israel Deaconess Medical Center. But Jeffrey and Cathy Woodman of Southwick say their son must have been deprived of oxygen for at least four minutes because he suffered significant brain damage.

"We don't know what happened," said Jeffrey Woodman, contending that police have left them with more questions than answers. "We are left to surmise that something occurred while he was in police custody that stopped his heart."

Woodman said his son had a preexisting heart condition, but he led an active life and had been playing basketball earlier that day. He said doctors told him his son's heart was functioning normally.

Thomas J. Nee, president of the Boston Police Patrolmen's Association, said he understands the family's anguish, "but nothing those officers did that night caused his death."

He said that the officers, who have not been identified publicly, have cooperated with the investigation, and that the family's questions will be answered.

David Woodman, who was charged with drinking in public and resisting arrest, remained hospitalized after the incident and awoke June 23 from a medically induced coma. His parents said he recognized them but had difficulty communicating and whispered, "What happened?"

He smiled at a Globe reporter during a brief visit Thursday, spoke softly to his parents, and appeared confused. A large scrape was visible near his right eye. On Saturday, he was asking to go home, according to his parents, who believed he would survive and face lengthy rehabilitation.

At 2:30 a.m. yesterday he died at the hospital. The family is awaiting autopsy results.

Jake Wark, spokesman for Suffolk District Attorney Daniel F. Conley, said Conley "pledged a thorough and impartial review of the facts."

The Boston Police Department launched an internal investigation shortly after the incident into how the officers handled Woodman and will join the district attorney's office in investigating his death, Elaine Driscoll, a spokeswoman for the Boston police, said yesterday. Several officers were treated for stress and have returned to work, she said.