US singer Ray J has hit back after being accused of supplying Whitney Houston with cocaine - including the dose that led to her drowning death.
A spokesman for the 31-year-old singer, songwriter, record producer and actor denied the claims - and said he did not even know Houston had begun using the drug again.
Leolah Brown , the sister of Houston's ex-husband Bobby Brown, appeared on US television on Thursday where she suggested Ray J was to blame.
But the singer's representative told celebrity website TMZ that her allegations were "absolute BS".
Houston , 48, was found dead in the bath of her Beverly Hills hotel room on the eve of the Grammy Awards last month.
She died from accidental drowning due to the effects of cocaine use and heart disease.
Several bottles of prescription medicine were found in her hotel room, but coroner's officials said they were not in excessive quantities.
Coroner's spokesman Craig Harvey said cocaine metabolites were found in Houston's system, and it was listed as a contributing factor in her death.
He said the results indicated Houston was a chronic cocaine user.
The singer was buried in a New Jersey cemetery next to her father after an emotional four-hour funeral service.
It was attended by friends, family and superstars such as Oprah Winfrey, Tyler Perry, Alicia Keys, Mariah Carey, Mary J Blige, Jennifer Hudson and Roberta Flack.
Ray J, whose real name is William Ray Norwood Jr, was one of those who was at the funeral on February 18, reaching up to touch the casket after which he sat in his pew crying.
Houston was one of the world's best-selling artists from the mid-1980s to the late 1990s.
Her hits included I Wanna Dance With Somebody, How Will I Know, The Greatest Love Of All and her cover of Dolly Parton's I Will Always Love You.
But, as she struggled with drugs, her majestic voice became raspy, and she could no longer hit the high notes.
Interest in her music has skyrocketed since her death, pushing her songs back into the charts and onto the radio.