Earlier this month, police successfully tracked Mr Plowright's mobile phone and found that he may never have left the Perth area on the night of his disappearance.

Following inconclusive tests on a stain on Mill Road at Perth last week, and a reported sighting of the 20-year-old last month, police have decided to retrace their steps.

They will use a helicopter and kayaks to look for traces of Mr Plowright in the coming weeks.

Police are also revisiting three key witnesses and double-checking every lead, as the search for the social photographer continues.

Deloraine detective inspector Scott Flude said a chopper will scale the river on Friday if the weather permits it.

``We won't fly unless it's perfect,'' he said.

Police do not suspect foul play in Mr Plowright’s disappearance. 

He was last seen leaving a party at Perth about 9pm on May 30, wearing a grey hoodie, jeans, bright-coloured Converse shoes and glasses. 

A large-scale search of Perth in mid-June was Tasmania’s largest missing persons search in 30 years, but it returned no trace of Mr Plowright. 

Tasmania Police has seized control of his Facebook page in a bid for clues. 

Mr Plowright is described as 175 centimetres tall, of slim build with brown hair. He is of Thai descent. 

Police urge anyone with information to call Crime Stoppers on 1800 333 000 or Launceston police on 131 444.