LOS ANGELES –
California Department of Alcoholic Beverage Control investigators also want to know if Lohan or others were served after hours, agency spokesman John Carr said.
Videos show Lohan leaving Hollywood's Les Deux club at 3:30 a.m.
Alcohol cannot be served in California after 2 a.m.
The Department of Alcoholic Beverage Control told the Beverly Hills Police Department it wants to review witness reports and other evidence to determine if a formal investigation is warranted, Carr said.
Les Deux spokeswoman Marissa Knies said Lohan had dinner and wasn't drinking.
"Because of the enormous paparazzi presence outside of Les Deux that night, we allowed her to stay late and wait for her friends," according to a statement released by Knies.
Lohan, who turns 21 on July 2, was behind the wheel of a Mercedes-Benz that was heavily damaged when it crashed into a curb and bushes on Sunset Boulevard in Beverly Hills early Saturday.
Lohan was arrested for investigation of driving under the influence. Her publicist announced the actress entered a rehabilitation facility on Monday.
"We have a duty to check on these things whenever there's a report of a minor involved in a crash," Carr said, noting "underage drinking is a huge problem in the state of California."
Some 1,574 people were killed in alcohol related vehicle crashes last year and about 200 involved underage drinking.
There have been 10 recent enforcement operations involving Alcoholic Beverage Control and Los Angeles police officers checking Los Angeles area clubs, Carr said. The agency has four investigators in Los Angeles.
Club Teddy's at the Roosevelt Hotel in Hollywood paid a $3,000 fine on May 4 for accusations last year that they sold contaminated beverages and sold alcohol after hours, Carr said.
There's also a pending investigation now in the hearing process against Hollywood Boulevard's Club Mood, another popular nightspot for young Hollywood, Carr said.
There are no pending ABC enforcement actions against Les Deux.
"We do investigate any time we get complaints when someone underage is being served. Anyone under the age of 21 cannot be sold alcohol in California."
If that does happen, Carr said it can result in a fine, suspension of the club's ABC license to sell liquor or revocation of their liquor license.