The CBI on Monday questioned the doctor in charge of the hospital for inmates at the Presidency Correctional Home in connection with a purported letter sent by arrested Trinamool leader Kuntal Ghosh.
Kuntal, who was arrested by ED in January for his alleged involvement in corruption in school recruitments, has accused central agencies of pressuring him to implicate Abhishek Banerjee, Trinamul second-in-command, in the case.
He sent a letter to the special CBI judge stating that the central investigating agency was putting pressure on him to name Trinamool Congress leaders.
Kuntal has been in the custody of the CBI and the ED. He complained of alleged pressure by the two agencies a month after he was lodged in the Presidency Correctional Home.
Responding to a summons, P.K. Ghosh, the doctor, went to the Nizam Palace office of the CBI on Monday morning.
"We wanted to know if Kuntal Ghosh was tortured in the correctional home as he has alleged and whether he underwent any treatment at the hospital of the correctional home following the alleged torture," said a senior CBI officer.
Monday's questioning of the doctor was preceded by a team of CBI officers questioning Debasish Chakraborty, superintendent of the correctional home, earlier this month.
The officers had wanted to know from Chakraborty if there was any CCTV footage of Ghosh writing the letter or if he had verbally complained about the alleged excesses.
In May, a CBI team had turned up at the correctional home to question Kuntal about the purported letter and spent several hours there.
The team had asked Kuntal whether he had penned the letter to the CBI judge on his own or under instructions from someone. Sources said Kuntal was also asked to explain the sequence of events leading to interrogators allegedly forcing him to name Abhishek and how he countered this. All the statements were recorded and later written down in Kuntal's presence.
"We will collate all the statements before drawing up our observation about Kuntal's allegation against officers of the agency," the CBI officer said.