Bobby Brown's family can no longer visit Bobbi Kristina in hospice -- they've been banned because security guards believe one of them took the deathbed photo that's being shopped around.
Sources close to the situation tell us the security team at the hospice informed Whitney Houston's family there was evidence incriminating a Brown family member as the person who snapped the pic.
We're told Bobbi Kristina's estate -- run by her legal guardians -- made the decision to ban the Browns. We're also told although they know the culprit ... they're not naming names at this point.
TMZ broke the story -- someone is selling the pic to the highest bidder, and has already contacted several websites and magazines. So far, it has not been published.
We're told the ban does not affect Bobby. On Sunday, he told us he was committed to finding the person responsible for the pic.