Bank robbery suspect David James Roach, 27, is still being held in Thailand, as efforts by the authorities to repatriate him to Singapore have been at a standstill for at least two months.

Roach, a Canadian national, is accused of robbing the Standard Chartered Bank in Holland Village on July 7.

He allegedly handed the teller a note with his demands, before fleeing to Bangkok on the same day with about $30,000 in cash.

In response to media queries, a police spokesman said Singapore remains in touch with the Thai government to repatriate Roach. The spokesman said this includes the return of evidence that was seized from him.

The authorities declined to give details of ongoing negotiations between the two countries, which do not have an extradition treaty.

In August, the Attorney- General's Office in Bangkok reportedly rejected Singapore's request to extradite Roach, saying it was "not in the position to consider it".

Roach has been held at Bangkok's immigration detention centre since his arrest on July 10 at a backpackers' hostel. He was found with 700,000 baht (S$28,000) in cash, as well as a notebook detailing his escape plan, which included stopovers in Chiang Mai and Dubai.

The Thai authorities cancelled his right of stay in the country after Singapore issued a warrant for his arrest. But as an immigration offender, Roach would be deported back to Canada if he cannot be extradited.

Thai immigration police chief Nathathorn Prousoontorn had previously said the Canadian government was looking to have Roach deported back home.

Criminal lawyer Amolat Singh noted a possible complication could be that "Canada may want him handed over to them instead".

In addition, "Thailand may not consider the evidence (to extradite Roach) as convincing or compelling enough", he said.

Roach had left his home in eastern Canada to backpack across the world about a year ago, and was apparently on his first visit to Singapore when he allegedly carried out the first successful bank robbery here in more than a decade.