Australians on holiday in Bali have been warned to stay vigilant after numerous suspected 'snatch and grab' jewellery thefts.

Diego Palhano, from Brisbane, was leaving a nightclub in the popular Seminyak tourist district on May 12 when a thief on a motorbike ripped a necklace from him.

In footage published by The Daily Telegraph, Mr Palhano can be seen being dragged along the ground by the thief, who held onto his necklace, a family heirloom.

He said he did not suffer injuries to his legs. 

The clasp then broke and the suspected thief could be seen riding away.

'I actually ran to catch him, but, well, as he was with the motorbike; it was impossible,' Mr Palhano said.

The necklace, valued at $30,000, belonged to Mr Palhano's great-grandfather. 

He is now offering a 70 million Indonesian rupiah reward, about $A5,591, for its return.

Mr Palhano, who considers Bali a second home, said the incident has left him shaken.

'All the violence in this… It's a little bit more than just upsetting,' he said. 

He is among 10 Australians who have been robbed in similar circumstances along beachfront areas in Indonesia. 

In May, police arrested a local man who used a motorbike to snatch a gold necklace from a 67-year-old Australian woman in Legian, a five-minute drive south of Seminyak.

The man was later identified, arrested and charged with theft using violence, an offence which carries a maximum sentence of nine years in Indonesia. 

The Australian woman's stolen necklace was recovered.

Local police have increased night-time patrols along the Legian to Seminyak strip while warning tourists to exercise caution. 

'Tourists should take better care of their own safety … avoid travelling alone, avoid wearing conspicuous jewelry, and, at a minimum, walk with a companion,' Bali Police spokesperson Sr. Comr. Ariasandy said.

'In other words, they need to pay attention to their own self-protection. They should avoid creating opportunities for criminals.'