Former world welterweight champion Kell Brook has said he is struggling with retirement and seeking help for mental health problems.
His comments follow a video published by the Sun newspaper showing him appearing to snort a white powder at a party.
Brook, 36, retired from boxing in May following a career that saw him record 40 wins from 43 professional fights.
“I messed up. I hold my hands up,” Brook wrote on Twitter.
His manager Terry Thompson told the Sun that the video was “a joke” and Brook was just “having a laugh”.
Brook told the Telegraph last year his decision to quit the sport was because his “heart was no longer in it” and that he had “nothing left to prove.”
In Thursday’s tweet, he added: “It’s no secret that I struggle with mental health and I’m finding retirement really hard.
“I’m actively seeking the help I need to get me on the right path. Again I apologise for the hurt I’ve caused.”
Brook held the IBF world title from 2014 to 2017 after claiming the crown by beating American Shawn Porter on points in California.
He previously said he used a counsellor to help him overcome depression after losing his title in a fight against Errol Spence, during which he broke his eye socket for the second time.
Brook’s final bout was a sixth-round victory over bitter rival Amir Khan 12 months ago, but in January Liam Smith said fighting the Sheffield man was an option after his win over Chris Eubank Jr.