In the pic, Janet and her brother Jermaine are in front of the Calabasas compound ... clearly engaged in a heavy conversation.
We're told the photo was taken within the same hour LA County Sheriff's deputies went to Katherine Jackson's home ... after one family member accused another of a physical assault.
The Sheriff's Dept. isn't saying if Jermaine and Janet were the ones involved in that dispute.
As we previously reported, Janet and Jermaine have a lot to discuss -- the letter they and 3 other siblings signed, demanding the Executors of Michael Jackson's Estate step down ... and Katherine Jackson's puzzling trip to Arizona ... a trip some claim is a brainwashing mission.