Model Kate Moss has apologised to "all the people I have let down" and says she takes "full responsibility" for her actions after drug-taking allegations.
The model is being investigated by Scotland Yard
Moss, 31, has been dropped by clothing chain H&M after photos allegedly showing her taking cocaine appeared in a newspaper.
Chanel says it has no plans to use her again soon and Burberry has cancelled an advertising campaign featuring her.
The drug allegations are being investigated by Scotland Yard.
"I take full responsibility for my actions," she said in a statement.
"I also accept that there are various personal issues that I need to address and have started taking the difficult, yet necessary, steps to resolve them.
"I want to apologise to all of the people I have let down because of my behaviour, which has reflected badly on my family, friends, co-workers, business associates and others."
She said she was trying to "stay positive" with the "invaluable support and love I have received".
'Shocked and dismayed'
Metropolitan Police Commissioner Sir Ian Blair, speaking to journalists at the Police Superintendents Association Conference in Warwickshire on Wednesday, said he had been personally involved in the decision to launch an investigation.
He said: "We have to look at the impact of this kind of behaviour on impressionable young people and if there is evidence something should be done about it."
It has not been confirmed whether police will interview Moss, who had declined to comment on the claims until Thursday's statement.
It came hours after Rimmel, owned by cosmetics giant Coty, became the latest fashion brand to distance itself from Moss over the allegations.
The firm said it was "shocked and dismayed" by press claims about the model's behaviour and said it was "reviewing her contract".
Senior figures at Rimmel were said to be deeply concerned about the example the model was setting.
On Tuesday, H&M said that continuing to use Moss would be "inconsistent with its clear dissociation of drugs".
On Wednesday, Burberry followed suit, saying it had agreed with Moss it was "inappropriate to go ahead".
However, it added: "Kate has always been a fantastic model and highly professional for Burberry."
Hours earlier, Chanel had announced it would not be renewing the model's contract to be the face of its Coco Mademoiselle perfume.
Meanwhile, Gloria Vanderbilt denim, which used Moss in a series of magazine advertisements, said on Thursday it was "re-evaluating" her contract.
Moss also has contracts with designer brand Christian Dior and New York jeweller H Stern.