The Delhi Police are probing a cyber heist in which suspected Isis hackers have routed around Rs 5-6 crore in payments made to a Delhi-based firm to the bank accounts associated with Islamic State (Isis) in Turkey.

Delhi Police Commissioner BS Bassi learnt about the heist on Saturday and an FIR was registered at an undisclosed police station. A special team has reportedly been formed to investigate the heist, considered biggest in Delhi in 2015, The Times of India reported.

According to the police, the hackers routed the payments made by the Delhi firm's client from London. It is further suspected that the email account of an employee was hacked to route the money.

The police are suspecting the Isis link because the money was routed to Turkey and also because the London client was working for the victims of the Isis-occupied parts of Syria and for refugees in neighbouring countries.

"The probe is at an initial stage. It is too early to rule out the role of IS in this massive cyber heist as we are indeed probing some Turkey-based hackers who may have terror or IS links," a senior police officer told the TOI on condition of anonymity.

The Delhi firm reportedly works as a consultancy and advisory firm to assist development and social projects in India and other parts of the world. It had been receiving payments from its London client to its account with Kotak Mahindra Bank until October, when the payments suddenly stopped.

The firm contacted its client in London and learnt on Friday, 18 December, that he had made all the payments. The firm's vice-president ordered an internal inquiry that reportedly revealed lapses within the administration. The firm then filed a complaint with the police.