The agency conducted the voice sample test of the two leaders purportedly seen in the sting footage, which had surfaced in 2016 ahead of the West Bengal Assembly polls.
Roy and Mitra are among the ten leaders and ministers of the Mamata Banerjee-led Trinamool who have been summoned by the CBI for the test.
The Central Bureau of Investigation (CBI) On Monday had also conducted the voice sample test of West Bengal Panchayat Minister Subrata Roy and senior IPS officer S.M.H. Mirza.
Saugata Roy, the MP from Dum Dum, had earlier appeared before the Enforcement Directorate for questioning in the case as the agency is also probing the money trail in the case.
Following the release of the footage, the CBI lodged an FIR in April 2017, on a court order, naming 13 Trinamool leaders and have interrogated many of them. The purported footage was also sent for forensic examination.
On August 28, the CBI grilled Trinamool MP K.D. Singh, Samuel and former party leader Mukul Roy in the case. Roy, after quitting the Trinamool, had joined the BJP in November 2017. He was former aide of Banerjee, and had a fallout with her in 2015 when his name cropped up in the Saradha scam as well as the Narada sting operation.
( With inputs from IANS )