Some of the NEM cryptocurrency heisted from Tokyo-based virtual currency exchange Coincheck Inc. last week was sent to bourses in the United States and New Zealand early Thursday, a Japanese member of a Singapore-based NEM promotion group said the same day.

"The investigative authorities in several countries are making moves" in relation to the theft of the cryptocurrency worth 58 billion yen, or $532.6 million at the time, Takao Asayama, one of the council members of Foundation, said in an interview.

Some 260,000 customers have lost their deposits in the largest-ever cryptocurrency theft last Friday.

Coincheck provided police with system logs on Wednesday, while the police are gathering information from its employees. They are also expected to launch a full-fledged investigation into the case, suspecting it violated the unauthorized computer access law.

The exchange has halted the deposit, withdrawal and trading of NEM as well as trading of other cryptocurrencies and Japanese yen.

The company has said it will reimburse NEM holders to the tune of 46 billion yen, but worries have spread among customers as the amount is low under the current exchange rate and details of the compensation have not been announced. Foundation is tracking the stolen cryptocurrency, Asayama said. He said it is unclear whether the NEM sent to overseas exchanges has already been converted to cash, but it is unlikely.

A group of lawyers are planning to form a defense counsel for victims of the massive heist and file a lawsuit with the Tokyo District Court later this month to demand Coincheck reimburse the lost cryptocurrency. Several depositors have already asked the group for help.

"We intend to take steps after learning depositors' situations and requests," said Kanehito Kita, a lawyer who leads the group.

The perpetrators of the hacking attack have dispersed the stolen NEM coins to around 20 digital addresses in an apparent attempt to avoid being traced. Foundation has said its team of experts "tagged" the stolen cryptocurrency as tainted funds, making them easy to verify if withdrawn from or deposited with regulated trading platforms.

The popularity of digital currencies has increased expectations of their wider use, but the latest heist has sparked debate on how to regulate the decentralized technology.

Currently in Japan, virtual currency exchanges are required by law to register with the government. There are 16 registered exchanges and another 16 exchanges that are pending approval, the latter including Coincheck, according to the Financial Services Agency.

Coincheck has revealed its NEM accounts are managed on a system accessible via the internet, although the FSA urges exchanges to keep virtual currencies offline as much as possible in its guidelines.