May 16 (UPI) -- Smokey Robinson is under criminal investigation for sexual assault after he was accused of years of sexual abuse in a lawsuit filed by four former housekeepers.

The Los Angeles County Sheriff's Department announced the investigation on Thursday, saying it "is in the early stages," while providing no further comment.

"Our clients intend to fully cooperate with LASD's ongoing investigation in the pursuit of seeking justice for themselves and others that may have been similarly assaulted by him," John Harris and Herbert Hayden, lawyers for the four women, said in a statement.

Robinson's attorney, Christopher Frost, said he and Robinson "feel confident that a determination will be made that Mr. Robinson did nothing wrong."

"The record will ultimately demonstrate that this is nothing more than a manufactured lawsuit intended to tarnish the good names of Smokey and Frances Robinson for no other reason than unadulterated avarice," Frost said.