London - British athletics great Christine Ohuruogu who was crowned 2008 Olympic champion in the women's 400 metres, announced she is retiring on Saturday.
The 34-year-old - who indicated last year this season would be her last - failed narrowly to defend her Olympic title in London in 2012, taking silver behind great rival Sanya Richards-Ross.
Ohuruogu also won the world outdoor title on two occasions in 2007 and 2013.
"Today is the start of the British Championships and, as I won't be there competing, I feel it is a good time to formally announce my retirement from competitive athletics," she said in quotes cited by the BBC.
"I didn't feel ready to retire after last season but a combination of my studies and a niggling injury restricted how much training I was able to do this year."