Chaudhary, who sworn in the chamber of assembly Speaker Brij Bihari Lal Butail, has been booked for murder by Haryana Police.
He was brought here, where a large number of his supporters were assembled, in the morning from Ambala jail under a heavy security cover.
He is one of the four suspects in the murder of a 24-year-old woman in Panchkula in Haryana Nov 22.
"It's a political conspiracy by my political rivals. I am innocent," he told reporters soon after taking the oath.
On being asked that he confessed his crime before the police, he said: "It's a police theory. I have full faith in judiciary. I have never confessed that I have committed the crime."
Ruling out the possible of resigning as a legislator in the wake of the J.S. Verma Committee report that the legislators involved in woman-related crime should morally resign, he said he would come out clean.
"I will continue to work as a legislator. Even people are contesting elections from the bars. I have just submitted a list of his priorities as a legislator to the speaker," he said.
After evading arrest, Chaudhary had surrendered before a Panchkula court Jan 8, the day other legislators took oath.
Chaudhary is a first-time legislator from Doon in Solan district. He is the son of four-time Congress legislator Lajja Ram.