Siblings Sagar and Reema Thakkar fled the country as police began the raids in the call centre scam.
When the teams of Crime Branch of Thane Police were busy in raids in the call centre scam, its mastermind Sagar Thakkar alias Shaggy was fleeing the country in the early hours of October 5, officials said.
Crime branch teams raided seven call centres at Mira Road in adjoining Thane district, in the multi-crore scam in which US citizens were cheated of millions of dollars.
Police raids were conducted on the night of October 4-5. About 70 directors and key persons associated with these call centres were arrested and 700 employees detained.
During the interrogation of the arrested directors, police learnt about Mr Thakkar. However, by that time, he had left the country.
Police issued a LOC (Look Out Circular) against Mr Thakkar on October 7, two days after his escape, officials told PTI. He is suspected to have fled to Dubai.
As the investigation started, a key accused and Mr Thakkar's elder sister, Reema Thakkar, also fled the country from New Delhi on October 8.
Police are now trying to get information from immigration authorities about how both key accused fled the country.
Investigators say Mr Thakkar began working at the age of 16 with his mentor Jagdish Kanani, who had worked in call centres abroad.
Mr Kanani trained him to cheat US citizens by starting fake call centres, they said.
Meanwhile, investigators on Thursday told a court in Thane that they have identified transactions worth Rs 25-30 crore in the call centre scam till now and that it will take a long time for them to arrive at the actual figure given the magnitude of the scandal.