Phillips Idowu has pulled out of the triple jump at the Aviva London Grand Prix - just three days after insisting injury was not behind his long lay-off this season.

Olympic silver medallist Idowu has competed just three times in 2012, with his last appearance coming in Eugene, Oregon on June 1. He struggled to hit top form in that event with leaps of 16.43 metres and 17.05m before a foul in the third round, after which he took no further part in the competition.

The 33-year-old subsequently withdrew from meetings in Oslo and Paris and the Olympic trials in Birmingham, with UK Athletics head coach Charles van Commenee declining to clarify Idowu's situation due to issues of "medical confidentiality".

Idowu claimed on Wednesday he had never mentioned an injury and was happen to let the "rumour mill stir itself," but has pulled out of the competition at Crystal Palace just 25 minutes before it was due to start with a hip problem.

Marilyn Okoro had a point to prove in the 800m after being one of four athletes controversially overlooked for Olympic selection, which had prompted her to say she would quit the sport despite being named in the 4x400m relay squad for London.

But after finishing fourth in 2:01.32, Okoro said: "I am really disappointed (about the 800m), but my focus is now the 4x400m. I am still going to get an Olympic chance in London and I have to build on that."