Dennis Rodman could be in trouble yet again - this time for allegedly slapping a woman's behind.

The retired hoops star is under investigation after the woman accused him of whacking her behind in a bar near his home in Newport Beach, Calif., gossip Web site TMZ.com reported yesterday.

The Orange County sheriff's office is probing the incident, in which one source told the Web site that Rodman hit the woman so hard, he left a "major mark."

"A police report was taken and is currently with the sex crime unit," Jim Amormino, a spokesman for the Orange County sheriff, told TMZ.