"Until we hear more information or something sends us in a particular direction there's really nothing more we can do.''
He has light brown dreadlocks and is carrying a backpack.
Meanwhile, inquiries are continuing into the whereabouts of West Coast teenager Liam Stirling, who has been missing for five days.
The 15 year old, from Taylorville, was travelling from Haast to Greymouth on Wednesday when the bus he was on stopped for a break in Paringa at 3pm.
Liam got off the bus but failed to return, police said.
He was later seen walking south on State Highway 6 towards Haast. Police believe he may have been trying to get to his stepfather's home in Dunedin, or his brother's address in Mosgiel.
Ms Dunne said West Coast police had been in touch with authorities in Dunedin in case he was there.
"The most likely scenario is he was trying to get back to that area,'' she said.
"We believe he's gone of his own will and we just haven't managed to find him yet.''
Liam is about six-foot-three tall, with a thin build and light brown hair.
Anyone with information about either missing person should contact police.