A UFC fighter says a mystery visitor called at his home and left with a sample of his blood after he mistakenly took her for an anti-doping official.
American featherweight Dan Ige said he was used to routine visits from testers so thought nothing of it when the woman asked to take his blood.
He believes she meant to visit a neighbour but got the address wrong.
"I want to get my blood back. I don't want to get cloned or end up at a crime scene," said the 27-year-old.
He later told Flocombat: "There are people who could use my blood but I just gave it away for nothing."
Ige, who beat Scotland's Danny Henry at UFC Fight Night 147 in London in March, said he was woken at 6.30am by the doorbell ringing and answered the door to the woman telling him she was there to take his blood.
"I'm subject to testing at all times so did not think twice. I'm thinking Usada [US Anti-Doping Agency]," Ige explained, adding that he did not think to ask to see credentials.
"The lady was really nice, don't get me wrong. We get to the paperwork and I gave my name. I said: 'Ige, first name Dan.' And she's like: 'Oh, you're not John?' I'm like: 'John? No, I don't know who John is.'"
According to Ige, the woman checked his address and discovered she had the wrong house before leaving. "But she took my blood and everything - she still has it," he added.
The fighter, from Hawaii, said he later visited the nearby address the woman had given and spoke to a man, who confirmed he had an appointment to submit blood to a private laboratory.
Ige claimed he has been in touch with the laboratory but is yet to find out what happened to his sample.
A UFC spokesperson said: "The UFC has been in contact with Dan this morning, and while it looks like this sample collection was intended for a neighbour and completely unrelated to Usada or the UFC, we advised Dan to contact law enforcement and we will support Dan to track down the details of this mistake."