Authorities have warned of a dangerous new drug, potentially on its way to Australian streets, which is known as ‘flakka’.

The synthetic hallucinogen is scientifically known as Alpha PVP and combines the effects of ‘ice’ – or methamphetamine – and LSD. It is also known as ‘gravel’ and ‘zombie’.

Forensic toxicologist Andrew Leibie, from Safe Work Laboratories, said little was known about the drug’s specific effects.

Flakka is scientifically known as Alpha PVP. (9NEWS)

“How bad is it? Well, to be honest, we don’t even really know enough about it to tell you how bad it is,” he said.

There were rumours the drug was already available in Australia, specifically in Sydney, Mr Leibie said.

“I’ve heard stories in the greater Sydney area, in Newcastle and Wollongong, that’s it about $15 a pop,” he said.

Flakka is already available in Europe and America and had been implicated in balcony and vehicle deaths, Mr Leibie said.

The drug was being monitored, National Drug and Alcohol Research Centre Professor Michael Farrell said.

“It’s one of the new psychoactive substances, over 240 new psychoactive substances, being monitored across the world,” he said.

Synthetic hallucinogens are dangerous, NSW Police Force Detective Superintendent Tony Cooke warned.