Probe agencies have been asked by the Special Investigation Team (SIT) on black money to check and curb the use of cryptocurrencies as it reviewed their operation and circulation in the country and links to shady offshore transactions.

The SIT recently held a meeting in the national capital during which it was briefed about the overall scenario of the operations of this virtual currency in the country, media reports quoted officials as saying.

The SIT, as per the sources, called cryptrocurrencies like bitcoins “illegal” and asked probe agencies such as the Income Tax Department, the Enforcement Directorate (ED) and the Narcotics Control Bureau (NCB) to detect and stop their usage and check transactions being done over the Internet, including those with cross-border ramifications.

The panel, they reportedly said, would also prepare a report that would be submitted to the government in sometime.

“The government is the final authority to frame rules and law to regulate these virtual currencies and the SIT would provide its report to it on the subject,” PTI quoted a senior official as saying.

During the meeting, the NCB informed the SIT that about four cryptocurrency-fuelled drugs smuggling transactions have been unearthed in the country in the last over two years time while the tax department informed the panel about the searches it conducted on bitcoin exchanges across the country last year.

A report prepared by the banking regulator –the Reserve Bank of India (RBI) — was also taken up during the meeting, they said.

Finance Minister Arun Jaitley, in his speech on February 1, had said that cryptocurrencies were not legal and affirmed to eliminate their usage, reported PTI.

The RBI, in the past, has come out with three specific warnings to discourage public from investing in the virtual currencies, the report said.