The musician passed away on March 25 at the age of 71, but his death wasn't confirmed until Monday night (01.04.24) and no more details have been revealed. The news came as a blow to his former bandmate Midge Ure who led tributes - calling Chris "the glue that held the band together".
In a post on Facebook, Midge wrote: "We worked together, we played together, made music and directed videos together.
"We were instant friends as well as Ultravox comrades. Even after years apart we managed to pick up where we left off like the years in between never existed. You were the glue that held the band together.
"You were the logic in the madness and the madness in our lives. It was great to know and grow with you. You are loved and missed old friend."
Ultravox keyboardist Billy Currie added in a statement: "Hi People. So sorry to hear about Chris. Very shocked. We had some amazing times together. Laughing mostly."
Chris - real name Chris Allen - was born in London in 1952 and played in a number of groups before he formed a band called Tiger Lily band in 1974 with John Foxx, Stevie Shears, drummer Warren Cann and keyboardist Billy Currie, who a year later.
They later changed their name to Ultravox and were fronted by singer Foxx throughout their early years but he left to pursue a solo career in 1979 and was replaced by Midge Ure. They then went on to find huge success with their fourth album 'Vienna', which was released in 1980.
Chris co-wrote the album's iconic title track as well as songs including 'Dancing with Tears in My Eyes' and 'Reap the Wild Wind'.
The group drifted apart in the late 1980s, but got back together for a reunion tour in 2009 and their last album 'Brilliant' was released in 2012.