The former Team GB taekwondoka switched allegiance to represent Moldova earlier this year after he was controversially not selected for the 2012 London Olympic Games despite topping the world rankings at the time.
Lutalo Muhammad, who was selected instead and won a bronze medal, also lost his quarter-final.
Cook, the highest-ranked fighter at the competition and whose girlfriend Bianca Walkden represents Team GB, was beaten 8-7 by Portugal’s Julio Ferreira after a golden point round, while Muhammad lost 17-5 against home fighter Milad Beigi Harchegani
“I feel like I’ve let them (Moldova) down today and that’s why I’m very disappointed with myself,” a dejected Cook told reporters. “I came here for the gold medal and I always come to every competition expecting the gold medal.”
Cook still appeared angry about his 2012 snub, having said earlier this week that the British national anthem now meant nothing to him.
“(Representing Moldova) has given me the opportunity (to compete in Rio 2016) and I had to do it,” he said. “It wasn’t an easy decision of course, but it was the right decision.
“I did everything possible that I could have for London. I was world number one, I won all the tournaments that they put on the criteria but it wasn’t good enough then.
“I wasn’t going to put myself and my family through that again so that’s why I switched to Moldova. This is only my second competition for them. The support has been fantastic.
“They’re always here cheering me on. It’s been amazing, it really has, and I want to thank everyone for giving me the opportunity.”
Cook and Muhammad had been scheduled for a much-anticipated showdown in the semi-finals.
“Of course that would’ve been nice but it wasn’t meant to be,” Cook said. “He’s a fantastic fighter and I’m sure we’ll fight each other eventually because there are so many competitions.”
Source: Yahoo Sports News