LOS ANGELES (AFP) - Veteran US comedian Jerry Seinfeld is not autistic, he said in comments reported Thursday, two weeks after he'd suggested he was on the autism spectrum.

"I don't have autism, I'm not on the spectrum," he told Access Hollywood, adding he had been responding to an interviewer's specific question in his remarks earlier this month.

"I just was watching this play about it and thought, 'Why am I relating to something?' ...I related to it on some level. That's all I was saying," Seinfeld said.

The multi-millionaire actor - famous for his semi-autobiographical 1990s sitcom Seinfeld - had told NBC's Nightly News that he was "never paying attention to the right things."

"I think, on a very drawn-out scale, I think I'm on the spectrum," Seinfeld said.

"Basic social engagement is really a struggle. I'm very literal. When people talk to me and they use expressions, sometimes I don't know what they're saying," Seinfeld explained.

"But I don't see it as dysfunctional. I just think of it as an alternate mindset."

The cause of autism, a complex neurodevelopmental disorder characterised by social withdrawal, is thought to be roughly split between genetic and environmental factors, according to experts.