Republican presidential hopeful Ben Carson has admitted that he is "a little bit irritated" every time people compare gay marriage rights to civil rights.

Carson made the remark during a recent CNN interview where he also said that being gay is a choice. He claimed that men "who go into prison, go into prison straight—and when they come out they're gay."

Carson later said he should not have let his emotions get the better of him, and clarified that he was simply answering the question that was hurled his way.

"I was a little irritated, but I shouldn't have allowed that to enter into the discussion," he said.

He also offered a statement of apology, saying his harsh choice of language does not really reflect what is on his heart concerning gay issues. "I do not pretend to know how every individual came to their sexual orientation. I regret that my words to express that concept were hurtful and divisive. For that I apologise unreservedly to all that were offended," he said.

But Carson remains firm that marriage should solely be between a man and a woman only since this has worked fine for thousands of years already.

In the end though, Carson said he was happy with how things worked out, since the gay rights controversy has only made him stronger. In a survey commissioned by CNN/ORC, he landed seventh place among the Republican presidential hopefuls.

"They saw that as the opportunity to finally knock this guy out," he said. "And they thought that they had done it. Stick a fork in him, he's gone. They were jubilant. And now they're saying, 'I can't believe this guy's still here, are you kidding me?'"