The alcohol issue is back for the police department, with public officials and family members of a man who was shot by an off-duty officer clamoring for answers this week to speculation that the officer’s 19-hour delay in turning himself in could be because he was drunk at the time.

While there’s been no evidence to support this theory in the case of the shooting death of Jayson Tirado by Officer Sean Sawyer, the accusations have once again raised an occasionally thorny fact of life for the city’s police officers: A requirement that they be fit for duty at all times means that a beer — or maybe three — is the limit on their days off.

The department had already been wrestling with how to monitor alcohol consumption by officers following last year’s shooting death of Sean Bell in Queens, which involved undercover officers who had been drinking. Supervising officers decided the officers were fit for duty at the time, but Commissioner Raymond Kelly recently implemented a new policy requiring breathalyzers for all officers who fire at suspects.

In this week’s shooting, Mr. Sawyer left work on Saturday at 7 p.m., and headed home at around 5 a.m. the following morning. According to some published reports, he has admitted to having a couple of drinks, but has denied being drunk.

Under Mr. Kelly’s new policy, Mr. Sawyer would have had to take the breath test — had he notified the police about the shooting earlier than he did.

Police unions are suing to force the police department to repeal the policy, which they say is unnecessary.

“It’s a policy looking for a problem,” a police union official said, noting that a study by the Patrolmen’s Benevolent Association found that out of 38 shootings by off-duty officers since 1999, only three involved intoxicated officers.

At a Gramercy Park bar known for its cop clientele, Plug Uglies, a bartender who declined to give her name said that police from the nearby precinct often stop by after work.

“They have a few,” she said. “But they’re always well-behaved.”

Still, a professor at John Jay College of Criminal Justice, Jim Curran, said in an interview yesterday that just as in the larger society, alcohol is a widespread problem among police.

“It really is a curse for young people, and cops are relatively young people. Unfortunately it’s a problem for them too,” he said.