"She was paid $40,000 plus expenses by to just appear as if she had just dropped by the party," a source tells Radar. "Part of the deal was that she wasn't allowed to go out and party or be seen anywhere else."
Though rehab vet Lohan- who had been spotted drinking in recent months-has said she wants to surround herself with good influences, the party girl just couldn't say no because she needed the money.
"Lindsay is desperate for cash, so she took the gig," the insider explains. As Radar previously reported, shopaholic Lohan quickly blew through her $2 million OWN paycheck.
Now friends are worried the troubled star is once again racing down a dangerous path.
"Lindsay is doing the exact opposite of what she should be doing," a pal recently told Radar. "She is out of her f**king head."