Nick Gordon allegedly raised some red flags during the investigation with the police after he reportedly admitted that he changed his clothes after fighting with Bobbi Kristina Brown on the day she was found facedown on the tub in January this year.

Are the authorities thinking about upgrading the case into a murder investigation?

New York Police Department detective Bo Dietl told Radar Online that he was surprised that Nick Gordon's lawyers allowed him to confess that he changed his clothes.

"That sounds very strange - the part about changing clothes," the homicide detective said. "Obviously, [the reason] could have been the blood splatter on his clothes when she got her tooth knocked out - that could be a reason to change your clothes."

But there are also CCTV cameras around the house and there could be a footage of Nick Gordon assaulting Bobbi Kristina Brown as alleged by the lawsuit.

"If f they had these cameras going, they may have actually captured video of him assaulting her," he said.

Bobbi Kristina Brown's aunt, Leolah Brown, however insisted that Nick Gordon murdered her niece.

In an interview with Inside Edition, she insisted that "Nick murdered Bobbi Kristina."

"When Nick gets arrested, I think everything will fall like dominoes," she said. "I believe that several people wanted Bobbi Kristina dead... I think the purpose of her death was to gain full access to Whitney Houston's estate."

Leolah Brown didn't stop there, however, as she also alleged that Whitney Houston was also murdered owing on the similar circumstances surrounding her death and Bobbi Kristina's. The singing diva was also found in a bathtub in a Beverly Hills Hotel in February 2012.

"I believe that Whitney was murdered," Leolah claimed. "At some point we have to wake up and realize this is too close, too similar - mother, daughter, both in bathtubs... Something is very, very wrong with that picture."

Nick Gordon has denied the accusation that he murdered Bobbi Kristina Brown.