Spencer Matthews said he watched footage of his older brother Michael for the first time since he disappeared on Mount Everest in 1999 while making documentary Finding Michael.
The Disney+ film will see 34-year-old Matthews attempt to find the body of his brother, who vanished three hours after becoming the youngest Briton to reach the summit of Everest at the age of 22.
The former Made In Chelsea star - married to Dubliner Vogue Williams - said his brother Michael was "everything to me", and the pair were often described as "twins separated by time despite the age gap".
In the film, Matthews attempts to retrace Michael's steps with the help of survivalist Bear Grylls and "14 peak" record-holding mountaineer Nirmal "Nims" Purja – who leads the search and rescue mission.
Canadian climber Dave Rodney, who had been on the expedition with Michael, also features in the film.
Matthews said: "Dave in particular brought to the table footage from the 1999 expedition of Mike and Dave climbing and Mike’s attitude to the mountain and I actually had never, prior to flying to Canada to meet Dave, had never seen Mike on camera ever.
"We weren’t the kind of family that made home videos and when I said to mum and dad, when we agreed to make this documentary, I said I need all footage of Mike and they said 'We don’t have any’.
"Fortunately, Dave had this incredible film that I hadn’t seen so I saw it in Canada for the first time and it’s the first time I’d heard Michael speak since he was alive, since I was 10."
TV presenter and executive producer Grylls also explained his connection to Michael.
"Michael was a young man that I met a few months before he set off to climb Everest, I’d climbed it the year before," he said.
"Twenty years on to watch Spencer now as a man, as a father, as a husband wanting to try and recover his body and tell Michael’s story was a privilege to be a small part of.
"I’ve always felt a bit of a shadow and a friend to Spencer ever since I met him just after Michael died up there and to see his journey come full circle is special."
Matthews described the film as a "story about brotherly love" and hopes the film "moves and helps people", adding that the reaction so far had been "incredibly humbling".
Source: Press Association
