Bobby Brown's sister Leolah Brown is claiming that Nick Gordon is under investigation for attempted murder of Bobbi Kristina Brown -- read her open letter to Dr. Phil Credit: Jim Spellman/WireImage

Leolah Brown isn't holding back. Bobby Brown's sister is claiming in a new Facebook post that Nick Gordon is under investigation for attempted murder of her niece, Bobbi Kristina Brown. Leolah made the allegations in an open letter to Dr. Phil on Saturday, Mar. 7, just days after Gordon had a staged intervention with the psychiatric expert.

"Dr. Phil, With all due respect, Nick Gordon is under investigation for the attempted murder of my niece Bobby Kristina Brown," the post read.

"We have strong evidence of foul play," she added. "Until this investigation is completed by law enforcement, I would ask that you or anyone else not provide this individual a platform to spin this situation to his benefit."

Gordon, 25, found Bobby Brown and the late Whitney Houston's daughter facedown and unresponsive in their Atlanta, Ga., bathtub in late January. She's currently still in a medically induced coma. Gordon has since been lashing out on Twitter against the R&B singer and his family, and has not visited Bobbi Kristina at Emory University Hospital in weeks. Last month, Brown's lawyer released a statement to Us Weekly claiming that Gordon isn't explaining what happened to Bobbi Kristina.

On Friday, Mar. 6, TMZ reported that Gordon checked into rehab for drug abuse following his Dr. Phil sit-down.

"If Nick Gordon does not have the courage to speak with my brother Bobby Brown and/or law enforcement about what happened the day my niece's body was found in a bathtub, he does not deserve to have a platform to speak to anyone of your caliber until this investigation is concluded," Leolah continued on Facebook. "Respectfully, Leolah Brown."