Former Railway Minister Roy landed at the federal agency's office in Nizam Palace in south Kolkata at around 2.15 p.m.
The CBI had on Thursday evening issued a notice to Roy, asking him to be present at its Nizam Palace office on Friday. However, the former Trinamool Congress leader wrote back to the agency seeking some time to appear, citing pre-occupation with political programmes.
But the CBI sent him a second notice, summoning him on Saturday. Roy had then told mediapersons that he would be available for questioning after 2-30 p.m. on Saturday.
The CBI has apparently decided to summon Roy to cross-check the information provided by IPS officer S.M.H. Mirza, who was arrested in the Narada TV sting case on Thursday and has been remanded to CBI custody till September 30.
In the sting operation conducted by Narada News chief journalist Mathew Samuel in 2014, the IPS officer and a number of senior Trinamool leaders including Roy and former Mayor Sovan Chatterjee, both of whom have since jumped ship to the BJP were purportedly seen taking cash or asking for money be deposited elsewhere in return for promising favours to a fictitious company.
The footage was uploaded by the news portal in March 2016, ahead of the West Bengal Assembly elections.
Mirza, the first person to be arrested in the case, was heard referring to his closeness with Roy in a footage uploaded by the news portal. Roy, it is said, had asked Samuel to meet Mirza, saying he would be the go-between.
Roy has, however, claimed that none of the footages showed him taking any money. "Neither did I take any money, nor was I offered... I had asked the person who came to me posing as a businessman to meet Mirza in connection with getting land for his business," he said.
The CBI lodged an FIR in the case on April 17, 2017 after a preliminary inquiry revealed prima facie material for registration of a regular case relating to criminal conspiracy (IPC 120B) and under several provisions of the Prevention of Corruption Act.
( With inputs from IANS )