A Central Bureau of Investigation (CBI) officer said Mirza was taken to Roy's third floor flat on Elgin Road for videography in the light of the clip in the footage where he was seen talking over phone with someone whom he assured that an amount of Rs 1.70 crore had been deposited at the right place.
The officer said the agency had taken Roy's permission before coming to his flat and the former Union Minister was present and "cooperative" when Mirza was brought there.
"Roy was present. He was cooperative. We came here following permission given by him," the officer told media persons at the spot.
A day after Roy - the accused number one in the FIR filed by the CBI on the sting footage case - was grilled for two and a half hours by the sleuths, Mirza was brought to the apartment under heavy security, with a large group of reporters and television camera persons crowding around.
A videographer engaged by the CBI captured every details of Mirza's movement from the lane leading to the apartment complex right upto his stay inside the flat, where he was made to sit face-to-face with Roy.
"Videography was done as per identification by Mirza sahab that the huge cash transaction took place at this place," the CBI officer told waiting media persons.
Asked whether the amount was Rs 1.70 crore, he said: "The amount... huge amount".
To another query on how Mirza got the cash, the officer said: "I don't have any knowledge about that."
Asked whether Mirza has claimed that he gave money to Roy, he said: "Well there are allegations and counter-allegations."
However, the officer nodded in agreement to a further poser as to whether Mirza has claimed during interrogation to have given money to Roy in the Elgin Road flat.
On the other hand, Roy claimed there was a conspiracy to malign him and the BJP, as there was not a single clip in the sting footage showing him taking any money.
"There is a conspiracy against me. That's the reason I have said I am ready to face any probe. There was no cash transaction at my place. (Narada News editor) Mathew (Samuel) has shown in the footage every cash transaction that he did. But nothing of that sort was shown in the clips at my place.
"The conspiracy is to malign Mukul and the BJP at any cost. That's the reason all the perpetrators of corruption are being told to take my name in whatsoever manner. If there is any footage showing I have taken money, then I will accept whatever punishment is given to me," he said.
Calling the developments a "regular process" of investigation, Roy said the reconstruction was earlier done at all places of occurrence, but the CBI could not do it at his flat "due some problems I had".
"Today they did a part of the reconstruction. It is a regular process," he said.
Standing near the ground floor gate of the apartment complex, Mirza was seen gesturing to the CBI that he had on earlier occasion not climbed the stairs but used the lift. The sleuths then took him into the lift that went up upstairs to Roy's flat.
When a scribe approached Mirza and asked him whether he had paid money to Roy in the flat, the IPS officer said: "You please speak to the CBI IO (Investigation Officer). It's improper me to say anything now."
On why he has been brought to the flat, Mirza replied: "You heard, they have brought me for reconstruction of the crime."
( With inputs from IANS )