Whitney's daughter Bobbi 'on drugs hours after the funeral'.

Whitney Houston’s daughter Bobbi Kristina was allegedly “getting high” on drugs hours after her mother’s funeral.

US reports say the 18-year-old went missing straight after Saturday’s emotional, four-hour “home-going” service.

After leaving the New Hope Baptist Church in New Jersey, Bobbi Kristina dodged a family dinner to spend “time alone”.

But news website The Daily Beast – run by the same publisher as respected Newsweek magazine – cite two difference sources that claim she was “getting high” in a nearby hotel.

Adding that her gran Cissy was “beside herself” with worry, the source reportedly said: “Everyone was freaking out and calling Bobbi Kristina’s cellphone.

"It was so much commotion after the funeral that Bobbi Kristina just slipped away. It’s a horrible situation for everybody.

“They tried to save Whitney, and it didn’t work. Now with Bobbi Kristina, they fear the same thing is happening again and they won’t be able to stop it either.

“Bobbi Kristina is all Ms Cissy has left of Whitney. She’s so tired – but ready to fight again to save her grandbaby.”

US reports say the troubled teen was upset by a bust-up at the funeral between her father and Whitney’s family.

Bobby Brown turned up with a nine-strong entourage, despite being asked not to attend. He left after being told to go by security three times.

It was also claimed the family were still searching for Bobbi Kristina on Sunday as Whitney’s body was set to be taken to Fairview Cemetery.

A spokesman told The Daily Beast: “There was some confusion about Bobbi Kristina’s whereabouts last night, but she’s OK. She needed some time alone. She is going through a very hard time.”

Aspiring singer Bobbi Kristina was twice treated in hospital for severe anxiety in the days after Whitney, 48, was found dead in a bath at the Beverly Hilton hotel on February 11.

The Houstons are said to be considering admitting her to rehab, but deny that she uses drugs.