Lohan (l) plays an uncontrollable teenager in Georgia Rule

Dina Lohan said James G Robinson, CEO of Morgan Creek Productions, was "way out of line" for scolding her daughter in a widely circulated letter.

"I don't think it was a smart thing to do to a young girl," she told US TV show Access Hollywood.

Robinson allegedly called Lohan, 20, "unprofessional" for arriving late on the set of film Georgia Rule.

"You have acted like a spoiled child... alienated many of your co-workers and endangered the quality of this picture," he has been quoted as saying in the letter.

'Legitimate'

He is also alleged to have accused the Mean Girls star of blaming her most recent absence on heat exhaustion when he claims it was caused by "all-night heavy partying".

Lohan was recently seen in the romantic comedy Just My Luck

Dina Lohan, however, has insisted that her daughter's claims were legitimate.

"Lindsay was in 105 (degree weather) saying, 'Mommy, I feel sick'," she said in the interview, to be aired on Monday.

"She has asthma and in extreme cold or heat you can't breathe."

Dina Lohan did however admit that "there was one day when [Lindsay] was late and they worked the schedule around her".

Lohan was treated for overheating and dehydration last week following 12 hours of filming, according to her spokeswoman Leslie Sloan Zelnick.

In January she was treated in hospital in Miami after suffering an asthma attack.

In Georgia Rule, Lohan plays a troubled teenager at odds with her mother and grandmother, played by Felicity Huffman and Jane Fonda respectively.