Pune: The cyber cell of the city police on Wednesday evening busted a major bitcoin fraud and arrested eight people for running a Ponzi scheme. The arrests followed complaints lodged at the Dattawadi and Nigdi police stations.All the accused were associated with GainBitcoin and its CEO, cryptocurrency operative Amit Bhardwaj, who is in the eye of a storm for multi-level market (MLM) schemes offering unreal gains to investors.“GainBitcoin, through their new and phoney cryptocurrency investment scheme called ‘GB21’, duped investors by guaranteeing 10% monthly returns. Bhardwaj and his associates used to hold workshops to lure investors. We suspect around 8,000 investors in the city to have been swindled,” said Rashmi Shukla, Commissioner of Police, Pune, adding that several more persons were under the police radar.The complainants said they had invested in contracts worth 1 Bitcoins (BTC) each and valid for an 18-month period.On activation of the contract, the owner was to be paid around 10% of the contract value every month as mining income, equal to 0.1 BTC. At the end of 18 months, they were to have accumulated 1.8 BTC.“The accused had lured gullible investors by enticing them with phoney claims of massive returns. Instead of real Bitcoins, investors were doled out worthless crypto tokens issued by GainBitcoin called ‘MCAP’,” said Pankaj Ghode, a consultant and cyber expert with the Pune police.Till date, 25 people had lodged complaints, incurring losses totalling ₹ 2.25 crore, police sources said. The police has registered the offences under the sections of the prize chits and money circulation schemes (Banning) Act, IT Act and the MPID Act.