Doherty was said to be 'shocked and saddened' by Whitehead's death
Singer Pete Doherty was arrested last week on suspicion of supplying drugs following the death of heiress Robin Whitehead, it has emerged.
The 31-year-old was one of four people questioned on Friday and was bailed to return in April.
The body of 27-year-old Whitehead, who had been making a documentary about the Babyshambles singer, was found in a flat in east London on 24 January.
Drugs paraphernalia is understood to have been found at the property.
Two other men, aged 41 and 28, were arrested on suspicion of supplying a controlled drug.
The 41-year-old man, along with a 53-year-old woman, was also questioned on suspicion of attempting to pervert the course of justice.
Miss Whitehead had recently completed the film The Road To Albion, a documentary about Doherty's former band The Libertines, and had spent a lot of time with the singer.
In January Scotland Yard said her death was not being treated as suspicious.
Robin Whitehead - who referred to herself as Robyn - was the granddaughter of the late Teddy Goldsmith, founder of magazine The Ecologist.
At the time Doherty's spokesman said the singer was "shocked and saddened" by her death.