Christine Ohuruogu was a big-name absentee from the Olympic trials

Christine Ohuruogu was forced to pull out of the British Olympic trials in Birmingham on Saturday because she is not fully fit after a virus.

This year, the British Championships double as the trials for the Rio Games in August but Ohuruogu, who won 400m goal in Beijing in 2008, was an absentee.

The 32-year-old wrote on Twitter: "Sorry guys, won't be running today, I have been fighting a virus and not yet ready to resume racing."

A superb performer on the biggest stages, Ohuruogu followed her gold in 2008 with silver at London 2012, and was world champion in 2007 and 2013.

She finished seventh at the Diamond League meeting in Birmingham on June 5, behind compatriots Seren Bundy-Davies (fourth) and Anyika Onuora (fifth).

Despite having to miss the trials, Ohuruogu could still be a member of the Great Britain team in Rio.

Even if the first two finishers in the trial have run the Olympic qualification time twice, as required, the selectors have the discretion to add a third runner, and Ohuruogu has already achieved the times needed.