Image copyright AP Image caption Whitney Houston (l) with Bobbi Kristina Brown in 2011

The daughter of late American singer Whitney Houston has been found unresponsive in a bathtub in a home in Georgia, US police say.

Bobbi Kristina Brown, 21, was found by her husband and a friend, police said. They immediately started resuscitating her until police and medics arrived.

She was taken to a hospital in Roswell where she was said to be breathing.

Whitney Houston was found dead in February 2012, aged 48, in a bath in a hotel in Los Angeles.

A post-mortem examination later concluded she died of accidental drowning due to the effects of cocaine use and heart disease.

'Thoughts and prayers'

Ms Brown was found in the bathtub on Saturday morning, Roswell police spokeswoman Lisa Holland said.

She added that Ms Brown was now at North Fulton Hospital in Roswell, Georgia.

"They called 911, started CPR on her, and police arrived first," Ms Holland told CNN.

"We took over the lifesaving measures until the fire/rescue and an ambulance arrived."

"Please keep her and the family in your thoughts and prayers," USA Today quoted her as saying.

Whitney Houston was seen as the golden girl of the music industry in the 1980s and 90s, becoming one of the world's best-selling artists and the most successful soul singer of all time.

But the hits stopped in the mid-1990s after she began to abuse cocaine, marijuana and prescription drugs.

Bobbi Kristina was born after the singer's tumultuous 1992 marriage to hip-hop singer Bobby Brown.

The marriage became a public spectacle and ended in divorce in 2007.