Family of Kiwi man missing in Australia for over a week hopes 'power of social media' will help search

The family of a New Zealand man living in Australia who has been missing for more than a week are asking anyone with information to please contact police.

New South Wales police say Andrew Olphert, 35, was last seen at his home on Darwin Avenue in the Sydney suburb of Little Bay on Monday, June 19.

His family contacted police when he failed to return home that day and police now hold concerns for his welfare.

Mr Olphert is a Caucasian between 175cm and 180cm tall, is of medium build and has brown hair.

He was last seen wearing navy and white striped jumper and navy/dark coloured pants.

Mr Olphert's sister Lucy posted online about her brother's disappearance, saying "this is certainly one of the hardest things I've ever had to share".

"With little leads or information to go off right now we are hoping that the power of social media may be able to assist in finding my brother," she wrote.

"To my friends in NSW and to those who may have been in recent contact with him, please be vigilant and share this around the surrounding areas."

Anyone with information on his whereabouts should contact NSW Police on 1800 333 000 - that number can be reached from New Zealand by dialling 0061 1800 333 000.

Andrew Olphert Source: New South Wales Police