The six-time Olympic track cycling champion Sir Chris Hoy is expected to announce his retirement.
The 37-year-old has announced a media conference in his Scottish home city of Edinburgh later this week.
It is not clear whether Hoy will retire immediately or after the 2014 Commonwealth Games in Glasgow.
He won a first gold medal at Athens 2004, added three in Beijing four years later and two in London at the 2012 Olympics.
Hoy also has 10 world titles and two Commonwealth Games golds.
