The star died in April, with an inquest into his death subsequently launched.
According to BBC News, the coroner’s report said that he arrived at a friend’s flat while intoxicated on the drug, and later became locked on a balcony.
Timmy later fell to his death while trying to climb down, suffering “multiple traumatic injuries”.
The 36-year-old had been treated for skin cancer prior to his death, after being diagnosed with stage three malignant melanoma in 2016.
Following his diagnosis, the singer revealed he had found a lump under his arm. He underwent surgery to remove lymph nodes, but doctors later discovered lumps around his collar bone and neck.
At the time of his death, Timmy was fundraising for a charity skydive he planned to do on 3 May and had raised £5,000 for the Royal Marsden hospital.
Timmy’s bandmates, Mark Franks, Mike Crawshaw, Darren Everest and Lachie Chapman, released a statement at the time of his death, which read: “It is with the greatest sadness that we have to announce that our dear friend and brother Timmy has passed away.
“We know this news will be as heartbreaking for you all as it is for us. We appreciate your love and support at this difficult time.”
On Wednesday they issued another statement via Twitter, which read: “Timmy, our funny, talented, beautiful friend, bandmate and brother, was dearly loved and he is deeply missed.”
Timmy, who usually took lead vocals in The Overtones, joined the band in 2010.
Originally called DYYCE and then Lexi Joe, as The Overtones they achieved four top-ten albums in the UK and their debut, ‘Good Ol’ Fashioned Love’, reached number four in the charts.
Timmy took a break from the band following his cancer diagnosis but returned ahead of their tour, which they subsequently cancelled.