The famous Hollywood hotel wrote to Lohan on July 31 asking her to leave the premises because she had failed to pay a total of $46,350.04 (£29,300) in outstanding charges.
The letter was later obtained by TMZ and posted in full on the website, detailing the amount Lohan had spent on room service, the minibar and the restaurant.
A spokesperson for the hotel has now released a statement to E! Online claiming that its staff were not responsible for the leak.
"Chateau Marmont places guest privacy as a core value and upholds this privacy with paramount importance," the hotel said. "After investigation, it appears that a private correspondence between Chateau Marmont's general manager and Miss Lohan was leaked by a member of her entourage.
"We are as horrified, disappointed and troubled by this occurrence as Miss Lohan surely is. Obviously, this is a private matter between one of our guests and the hotel and we will continue to treat it as such."
Lohan has reportedly explained that she thought the producers of her Lifetime movie Liz & Dick were responsible for the charges, though a source has claimed that Lohan was only given a one-off payment of $5,000 (£3,155) to cover hotel expenses.