By ROBIN MIZRAHI and PATRICIA SHIPP

"Bring me a scuba diver!" That was Lindsay Lohan's bizarre and spoiled demand on the set of her new movie as she went on a rampage that would make any Hollywood diva proud.

The head of the studio making Lindsay's new film sparked headlines recently when he issued the young actress a stern written warning about her outrageous behavior — but The ENQUIRER has learned the REAL story behind the scathing letter.

On July 26, James G. Robinson — the CEO of Morgan Creek Productions, which is producing Lindsay's current film Georgia Rule — sent the 20-year-old actress a blistering letter, chiding her for acting "like a spoiled child" and costing the film company "hundreds of thousands of dollars" for not meeting production schedules.

Said a source: "From the first day of shooting, Lindsay's been a thorn in everyone's side.

"That day she was supposed to be on the set at 5 a.m. and didn't show up until 12 hours later!

"She didn't bother to call or make any attempt to explain herself.

"She just waltzed in at 5 p.m. and acted like nothing was wrong."

The movie's director has been forced to shoot around the actress or reshuffle scenes to make up for her absences, revealed the source. But Lindsay's tardiness is not the only reason the cast and crew are bristling. Lindsay's diva behavior has everyone on edge.

Pick up this week's ENQUIRER for all the details!