"Varun Gandhi was kept in a small cell, where he could not see anyone. Inhuman treatment was meted out to him. He was harassed and tortured," Naidu told reporters after meeting Varun in Etah District jail here.
The BJP leader claimed that Varun was implicated under a conspiracy of the Bahujan Samaj Party (BSP) and the Congress.
Naidu also accused Uttar Pradesh Government of manipulating the CD containing Varun's speech.
"The CD containing Varun's speech, has been manipulated and his voice was not there in the CD. There was nothing objectionable in his speech," he added.
He alleged that a gang of underworld was planning to attack Varun.
"There is a security risk for the leader in the wake of reports that a gang of underworld don Chotta Shakkeel had planned to attack him. There is a danger to Varun's life," he added.