An off-duty Suffolk County police officer had a blood-alcohol content more than twice the legal limit after he fatally struck another motorist while traveling the wrong way on Sunrise Highway in West Islip last week, Suffolk prosecutors said Wednesday.

Robert Scheuerer, 24, an officer in the Third Precinct in Bay Shore, had a BAC of .17 percent, according to toxicology tests performed by the Suffolk crime lab, said Robert Clifford, spokesman for District Attorney Thomas Spota. The legal state threshold for intoxicated driving is .08 percent.

Scheuerer had been drinking at a bar on Sept. 27 when he drove the wrong way on Sunrise, leaving other motorists swerving to avoid him before the accident that killed a van driver, prosecutors allege.

Scheuerer was arraigned Tuesday on a felony charge of reckless endangerment in the crash. He pleaded not guilty and bail was set at $150,000. The new evidence will be presented to a grand jury for possible additional charges, said Clifford.

“At this point, we have reason to believe the defendant was drinking at a bar prior to the crash,” said Assistant District Attorney Marc Lindemann, according to a transcript of Scheuerer’s hospital arraignment released Wednesday, in which Lindemann said the district attorney’s office had obtained a blood warrant for Scheuerer.

Several motorists “flashed their lights” to get Scheuerer’s attention as he traveled east on westbound Sunrise Highway in a 2000 Nissan Pathfinder SUV before the 4:37 a.m. crash in rainy weather, Lindemann said.

advertisement | advertise on newsday

“One tractor trailer had to slam on his brakes and swerve out of the way of the oncoming vehicle,” Lindemann said. “Another motorist had to pull over onto the shoulder to avoid a crash.”

William Petrillo, Scheuerer’s defense attorney, said Wednesday: “It would be unwise and irresponsible for us to comment on the specifics at this time, but it would be wise and responsible not to prejudge this case until the credibility of these allegations have been tested.”

Police said they are working to make a positive identification of the van driver using DNA.

A department spokesman declined to comment Wednesday.

The officer, on the force for a year, was suspended without pay hours after the crash, police said.

The new allegations against Scheuerer were revealed in a transcript of Tuesday’s arraignment, which Newsday was barred from attending by acting Suffolk County Court Judge David Morris. Newsday obtained the arraignment transcript Wednesday from a Suffolk courts spokeswoman.

In denying reporters access to the hospital arraignment — proceedings that by state law are public — Morris cited the Health Insurance Portability and Accountability Act, a federal statute designed to keep medical records confidential.