A non-verbal teen with autism is missing on the NSW Central Coast, sparking an urgent search-and-rescue mission.

Leif Courtney, 13, was last seen at his Mooney Mooney home about 7.30pm on Wednesday. He was wearing grey pyjamas with sneakers.

On Thursday morning, police began searching the Mooney Mooney, Kangaroo Point and Brooklyn areas for the boy.

NSW Rural Fire Service and SES volunteers joined the search, along with sniffer dogs and a rescue helicopter. However, by the middle of the Thursday afternoon there was still no sign of the teenager.

SES volunteers and locals search dense bush at Mooney Mooneey. Photo: AAP

“Understandably, the family are beside themselves,” NSW Police acting superintendent Kylie Phillips said.

She said there were “serious concerns” for the boy due to his medical condition and age.

“He likes apples, his favourite song is Fireflies and [he] loves chickens,” she said.

“Yell out apples. His family have advised he likes apples and that is something that is known.”

Tweet from @gracefitz_9

Leif’s father Allen Courtney told the Daily Telegraph that anyone who saw his son should not be afraid to approach him.

“He’s not afraid of crowds. Please approach him if he’s seen and just do your best,” he said.

Mr Courtney said Leif was non-verbal but often noisy, making “squealing noises or [repeating] things he’s heard”.

“He’s not normally worried about a crowd or noise, so don’t let that bother you. Don’t be worried about approaching him. You may need to grab an arm or hand to have him follow [you],” Mr Courtney said.

Leif is of Caucasian appearance, about 160 centimetres tall with a slim build and blond hair.

-with AAP