Mel Gibson. (AP Photo/Francois Mori, file)
The Academy Award winner sat quietly in a courtroom across from Grigorieva, a Russian musician, before Los Angeles Superior Court Judge Scott Gordon began a closed hearing today.
Gibson and Grigorieva have been sparring for months over custody and financial issues involving their infant daughter.
Investigators are looking into Gibson's allegation that Grigorieva attempted to extort him after their breakup earlier this year. Grigorieva has alleged Gibson struck her during an argument in January.
No criminal charges have yet been filed in either case.
