The British Olympic Association has written to triple jumper Phillips Idowu asking for details about the injury which has cast doubt on his chances for the Games.
Idowu, 33, failed to travel to a warm weather training camp in Portugal on Monday, prompting the BOA to seek clarification about his hip injury.
BOA spokesman Darryl Seibel told the Press Association: "Our chief medical officer Dr Ian McCurdie wrote to Phillips and his agent yesterday asking that he provide to Dr McCurdie the relevant medical records relating to his injury and the treatment he is currently receiving."
He added: "Those should be provided to our chief medical officer on a confidential basis. The basis for doing this is a clause in our team members' agreement that says athletes are required to provide details of any injury or illness that may impact on their performance during the Games."
A fully-fit Idowu would be one of the top medal hopes among British track and field athletes.
Idowu is due to compete on August 7 and his coach Aston Moore said he has chosen to stay in London for treatment from a private physiotherapist.
In a statement on Monday, Moore said: "In training recently Phillips has had an ongoing injury problem and we have not been able to go at things 100%.
"At the weekend Phillips told me he would continue to seek treatment from a private physio in London and would not travel to prepare in Portugal, although he may join us here later. He is an experienced athlete who I have worked with for more than four years and we will assess the situation again in the coming days."
Speaking on Saturday, when he carried the Olympic Torch in Stratford, Idowu told the Evening Standard: "I'm fine, I'm okay. Things are being blown out of proportion.
"Even if the build-up to the Games hasn't been what I wanted, I'll always come out and jump a season's best. I'll do everything I can to make sure I'm pain-free for the competition so that I can jump to the best of my abilities."
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