ORONO ? The sister of a Boston man who collapsed Sunday while in police custody and later died said authorities didn’t do enough to save her brother.

“If the police attempted CPR immediately it wouldn’t have turned out as bad as it did,” Meghan Donoghue, 20, of Boston said Wednesday, one day after family members decided to remove her brother, Paul Donoghue, 19, from a respirator that had been keeping him alive since Sunday.

The sister said doctors told the family that tests showed that her younger brother was brain dead. He died 10 minutes after they stopped the respirator Tuesday evening, she said.

Donoghue collapsed early Sunday morning while in police custody as Orono police officers sought to quell a fight in which two men were stabbed. An Orono police official described the incident as an “out of control melee” at the Park Street club Ushuaia.

An autopsy was performed on Donoghue’s body Wednesday, but a final determination on what caused his death is pending additional study, a spokeswoman for the Office of the Chief Medical Examiner said Wednesday afternoon. No other information was being released, although police officials reported earlier this week that the Bangor hospital had taken a blood sample from Donoghue for a toxicology test.

Donoghue said that her brother suffered a bad asthma attack and started to turn blue while he was in handcuffs and standing by a police cruiser. She said she was standing about 5 feet away, as close as police would let her get, and that he fell to the ground, still in handcuffs. She said that it was five to 10 minutes before medics arrived to help, despite pleas for the police to intervene.

“As soon as my brother passed out, they should have given him oxygen and CPR,” she said.

Her assessment contradicts police accounts that are included in court documents. Orono police Officer Mark Silk reported that as Donoghue’s breathing became more difficult, the man’s legs weakened and he slumped forward.

Silk supported Donoghue and other officers helped removed the handcuffs and they awaited medics, according to the police report. One ambulance was called to handle a stabbing victim found in the doorway of the club while a second was brought in to assist with Donoghue.

An Orono police official who could speak on the case could not be reached Wednesday night. A state police detective investigating the death has said that the officers were helping Donoghue and that they did what they could to save him.

The state police are investigating why Donoghue died, while Orono police are investigating what led up to the stabbings.

Two men, Raymond Russell, 33, of Albany, N.Y., and Diandre Arrington, 21, of Orono, were stabbed but their wounds were not life threatening, according to police. They were treated at local hospitals and later released. Arrington, was arrested at the scene and later charged with criminal trespassing.

On Monday, he pleaded not guilty to a criminal trespass charge in 3rd District Court in Bangor and he was released on personal recognizance.

Witnesses identified Donoghue as the assailant, although his sister disputed those accounts.

“My brother didn’t stab anybody,” asserted Donoghue, who was in the area over the weekend for the college graduation of an acquaintance. Donoghue said her brother didn’t even have a knife on him.

Donoghue collapsed after police took him into protective custody as they sought to calm a crowd that was growing outside the club.

Officers had been staked out across the street keeping an eye on the parking lot where police said there has been a “high volume of incidents that occur,” according to police documents. They saw a fight break out in the parking lot and went to investigate.

Orono police investigators are still piecing together what happened and have interviewed witnesses who were there, Orono police Capt. Gary Duquette said Wednesday.

There are many discrepancies in the accounts of what happened and some people are not cooperating, he said. Investigators are trying to enhance video tapes and possibly get still photos that could help identify what happened.

Duquette described the incident as an “out of control melee where it’s hard to pick out who was doing what.”

Meghan Donoghue doesn’t disagree with that assessment and said: “It was crazy, just everybody in the corner fighting.”

But Donoghue said her brother didn’t start the fight. Instead, she said, a friend was pushed on the dance floor by another club patron and the friend and her brother were confronted a short time later by about 10 people who began to fight with them.

Club employees broke up the fight but it resumed outside where her brother was chased down, she said.