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ET has learned that 'Transformers: Revenge of the Fallen' actress Isabel Lucas, the reported mystery passenger in Shia LaBeouf's weekend truck accident, went back to work on the movie's set on Monday.

Usmagazine.com reports that Lucas, 23, was in the passenger seat when Shia's truck was struck by another car in Hollywood early Sunday.

And there's more. The New York Daily News reports Lucas has been dating "Entourage" star Adrian Grenier for a number of months. Grenier reportedly offered no comment when asked how the Aussie siren was doing after the crash, according to the paper.

Lucas and the other other driver were treated for minor injuries at Cedars-Sinai Medical Center in L.A., while Shia underwent surgery on his hand. The 'Indiana Jones and the Kingdom of the Crystal Skull' star was also arrested on suspicion of DUI, according to a Los Angeles County Sheriff's spokesman.

In addition to the Australian TV series "Home and Away," Lucas' other credits include the upcoming vampire flick 'Daybreakers' opposite Ethan Hawke and the upcoming WWII miniseries "The Pacific."