A government official hinted at the possibility of a larger "conspiracy angle" to discredit the country's election process, hinting that the machine may have been taken to a European country.
Mumbai police had arrested Hari Prasad (42) in Hyderabad last Saturday in the EVM theft case.
Suspecting a bigger conspiracy, the official said, there seems to be a bigger picture.
"We are conducting a through probe to find out who was actually behind it, why it has been done and whether there is a conspiracy to discredit India's election process," the official said.
A demand was also made in Parliament for an all-party meeting to discuss the "vulnerability" of EVMs.
The BJP has been raising the issue of possibility of tampering of EVMs since general elections 2009. The arrest of Prasad also had political overtones with TDP chief Chandrababu Naidu batting for him.
An official said investigators have found that two Americans and one Dutch national had helped Prasad, technical coordinator of VeTA (Citizens for Verifiability, Transparency and Accountability in Elections), to show how the machine can be tampered with.
Besides, it is suspected that the EVM might have been smuggled out of India, possibly to an European country, deepening the suspicion that there could be a larger "conspiracy angle", the official said.