A senior CBI official told : "We have summoned Roy for questioning tomorrow (Friday) in connection with the case."
Names of Roy, a former Union Minister and ex-Kolkata Mayor Sovan Chatterjee also figured in the FIR filed by the agency in 2017. Both Roy and Chatterjee, once considered close to West Bengal Chief Minister and Trinamool Congress chief Mamata Banerjee, later crossed over to the BJP.
Others, whose names figure in the FIR, include Bengal Ministers Firhad Hakim, Subrata Mukherjee and Suvendu Adhikari, MPs Saugato Roy, Kakoli Ghosh Dastidar, Prasun Banerjee and Aparoopa Poddar, former state Minister Madan Mitra and MLA Iqbal Ahmed, all from the Trinamool.
The 13th accused, Trinamool MP Sultan Ahmed has since passed away.
The CBI has earlier grilled Roy on number of occasions and several other people connected to the case.
The agency, earlier on Thursday, arrested IPS officer S.M.H. Mirza - who was allegedly shown in the sting accepting Rs 5 lakh.
In the sting operation conducted by Narada News editor Mathew Samuel, who posed as a businessman, ahead of the 2016 Bengal Assembly elections, Mirza and a number of top Trinamool leaders were purportedly seen taking cash in return for favours.
The CBI lodged an FIR on April 17, 2017 against 13 people including Mirza and several Trinamool leaders, a month after the Calcutta High Court ordered it to conduct a preliminary inquiry in the case.
( With inputs from IANS )