The authorities were investigating the mysterious death on Tuesday of a young man in Queens whose face and back had been spray-painted blue by a drinking buddy, the police said.

Investigators did not immediately identify the victim, who was described as a 19-year-old man, or his friend.

The victim’s body, clad in boxer shorts, was found at the bottom of a flight of stairs, the police said. It was unknown whether a fall, excessive drinking or the paint had caused or contributed to his death, investigators said.

The victim and his friend worked together at a bar on Bleecker Street in Greenwich Village, the police said. They had been drinking heavily through Monday night into Tuesday morning at the friend’s apartment at 78-02 86th Avenue in Woodhaven, the police said