Athletics coach Lloyd Cowan, who helped Christine Ohuruogu to the Olympic 400m title in 2008, has died aged 58.
Cowan represented England in the 110m hurdles at the 1994 Commonwealth Games before becoming a coach.
As well as the Olympic title, Cowan coached Ohuruogu to 400m silver at London 2012 and 4x400m relay bronze in 2008 and 2016.
“We are deeply saddened by the passing of Lloyd Cowan MBE,” a UK Athletics statement said.
“Our thoughts are with his family and friends at this time.”
Cowan also guided England’s Andy Turner to Commonwealth and European 110m hurdles titles in 2010 and coached his son Dwayne, who won a 4x400m bronze at the 2017 World Championships.
Britain’s former Olympic 100m champion Linford Christie said on Twitter: “The world of track lost another family member today, and it hurt more than I could have ever imagined.”
Olympic heptathlon champion Jessica Ennis-Hill said she was “absolutely gutted”, adding “he always believed in me”.