Given problems with documentation and statements from some witnesses who contradict Brown's claims of work, prosecutors asked Brandlin to order Brown to repeat his service in Los Angeles.
Brown spent one-third of the hours he logged in Virginia working night shifts at a day care center in rural Virginia where his mother once served as director and where the singer spent time as a child.
A detective who checked on Brown's work nine times at the Tappahannock Children's Center found the singer, his mother and a bodyguard at the center on each visit.
The records said Brown waxed floors or performed general cleaning at the center.
A professional floor cleaner contracted to work at the daycare center told investigators he had been cleaning the floors during the months Brown reported working at the facility.
"Claims that the defendant cleaned, stripped and waxed floors at that location have been credibly contradicted," prosecutors said in the filing.
Brown's mother, Joyce Hawkins, no longer had a formal role at the day care center but had her own set of keys and coordinated her son's work at the facility, prosecutors said.
Murray stated in her filing that the police report on Brown's service was "at best sloppy documentation and at worst fraudulent reporting."
No one from Virginia's probation department oversaw Brown's hours, prosecutors said.
The motion noted that the only records the department has to indicate that Brown was supervised were officers' overtime sheets. Five of 21 days that officers logged overtime for Brown were spent providing security for the singer's concerts.
The allegations are the latest pre-Grammy controversy for Brown, who was arrested shortly after the 2009 ceremony for his attack on Rihanna. He has since returned to the awards show by performing and winning an award in 2011 for his album "F.A.M.E."
Brown and Ocean are competing against one other for the Best Urban Contemporary Album category at Sunday's Grammys.
AP writers Anthony McCartney and Ryan Pearson contributed to this report.
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