An 18-year-old has not been seen for more than two weeks.

Tee Dargaville, 18, from Mellons Bay, whose full name is Te Houtaewa Dargaville, was last spotted on Eastern Beach on May 31.

His father Fred is concerned for Tee's safety.

Mr Dargaville says his son has psychiatric problems but is not a danger to anybody except himself.

Tee left his father's Bleakhouse Rd house at about 7.30am on the Sunday.

"In the morning when he went missing we had breakfast together. He said he was going for a walk down the beach," Mr Dargaville says.

"He left and never came back."

Tee was barefoot and dressed in black tracksuit pants and a red hoodie.

Construction workers were the last people to see him that morning as he did acrobatics on Eastern Beach that day, before heading up an alleyway towards the tennis club.

"They noticed him because my son does sideways flips and stuff."

Mr Dargaville says one of the workers noticed Tee's behaviour was a bit off.

The Auckland teenager had been staying with his father in Bleakhouse Rd in Mellons Bay for the past month.

Tee is about 1.8 metres tall and of medium, athletic build.

Mr Dargaville says Tee has not accessed his bank accounts or been active on his Facebook account.

"There's a growing concern," he says.

Anyone with information should contact police on 2611300.

- © Fairfax NZ News