Karuppan, who was the self-styled godman's driver, told reporters here that the Swami had offered him Rs.20 crore to withdraw his charges against him.
"Since I refused, he is making calls threatening my life," Karuppan said.
Nityananda has been chargesheeted by police with rape, unnatural sex, cheating, criminal intimidation and criminal conspiracy. Four associates, including a woman, have also been chargesheeted.
Nityananda, who has a sprawling complex at Bidadi on Bangalore's outskirts, is on bail.
The chargesheet was filed by Bangalore Police Nov 27.
Nityananda, hailing from Tamil Nadu, was arrested from Himachal Pradesh April 21 after being on the run since March 3 when the video clip was telecast on several TV channels.
The chargesheet runs into over 400 pages and has statements by several women followers of Nityanayanda accusing him of forcing them to have sex with him, beating them and ordering them to get alcohol for him.