The controversial and self-styled godman is lodged in the jail ever since he was arrested by the state crime branch police in August this year.
"We are now ascertaining the authenticity of the purported interview that was broadcast by the TV channel on Friday last," said jail Superintendent Niranjan Das questioning its credibility.
The recorded voice would be matched with that of Roul's and all call details of the landline telephone of the jail would be examined, he said.
However, jail inmates are allowed to speak to their family members once in a week over the landline phone available inside the jail, but it happen only in presence of a warder, Das added saying the truth will come out after a thorough probe.
Pleading innocence on all charges and innuendos levelled against him, Roul has apparently made an attempt to blame the media for the smear campaign launched against him in the purported interview.