The news was first reported by the CBS television affiliate in Las Vegas, saying he was arrested on suspicion of possession of cocaine and Ecstasy at a pool complex at the MGM Grand hotel.
Stoll, 32, had been held at the Clark County Detention Center, but officials there Friday night said he was no longer in custody. Another person close to the case confirmed that information.
Bill Daly, the NHL's deputy commissioner, said in a statement to The Times: "We are aware of the reports tonight, and we obviously will follow up to understand the nature of the allegations that are being made. We are not in a position at this time to comment further until we have more information."
The Kings were informed of the matter Friday night.
"We are aware of police reports out of Clark County, Nevada, regarding Jarret Stoll," the team said in a statement. "Our organization is concerned and has begun conducting a thorough internal investigation.
"While we continue to actively gather facts, we are withholding further comment at this time."
Stoll, 32, has been with the Kings since the 2008-09 season, and was an integral part of their two Stanley Cup championship runs, in 2012 and 2014. The Kings missed the playoffs and their season ended Saturday.
Stoll is due to be an unrestricted free agent this summer. He is the longtime boyfriend of television celebrity Erin Andrews.
One of the times Stoll was in the news for non-hockey reasons was the summer of 2013 when he was rushed to the hospital after having suffered a seizure at his Hermosa Beach home.
Kings General Manager Dean Lombardi said then that Stoll was taken to a hospital in Torrance and released later that day.
Lombardi told The Times after the seizure: "The bottom line is that he's fine. Now the issue is what caused it.
"There are a myriad of things that can cause them."
The organization and Stoll remained mystified as to what caused the seizure. He had suffered a concussion in the team's playoff run that spring. He had also suffered one in the 2006-07 season while playing for the Edmonton Oilers and had one this last season.
The Kings' season was overshadowed by the arrest in October of Slava Voynov, who was charged with felony domestic violence after an incident involving his wife, Marta Varlamova.
Times staff writer Ryan Parker contributed to this report.