Young Thug Wanted for Questioning in Nightclub Parking Lot Slap

Cops want to have another chat with Young Thug, this time about whether or not he slapped a woman in the face in a nightclub parking lot ... TMZ has learned.

Police were called to Palace nightclub in Atlanta early Sunday morning to respond to a verbal dispute, which allegedly resulted in the rapper hitting a woman he used to work with -- 27-year-old Valerie Raven, aka Akbar V ... according to the report.

Akbar V claims she was arguing with Thug's fiancee, Jerrika Karlae, in front of the club when YT stepped in ... and slapped her on the left side of her face. Akbar said there were several witnesses, but Thug and Karlae had already left when cops arrived.

Law enforcement sources tell us they want to speak with Young Thug to get his side of the story. Akbar filed a report for battery, but cops say videos they've seen of the altercation don't show him making any contact.

We reached out to a rep for YT ... so far, no word back.