Rahul Kumar, one of this year's Intermediate science stream "toppers", has revealed how he zeroed in on the Vishun Roy College in Vaishali because he knew the college owner Bachcha Rai could rig the exam.

The Patna police special investigation team (SIT) probing the scam nabbed Rahul, one of the four Vishun Roy College students named in the FIR, on Wednesday from the residence of one of his relatives in Azampur village in Vaishali district.

Rahul, who had failed the board re-test and had gone into hiding, told a group of journalists - of which this correspondent was a part - that he is an adult.

"I was born on October 12, 1996," said Rahul, who hails from Shapur Patti village in Muzaffarpur. "After passing my Class X examinations from the DAV School in Muzaffarpur, I dropped a year and was preparing for IIT. Some students told me that Rai has solid contacts and he could easily make me a state topper. I thought that with high marks in the Intermediate examinations, I would at least get into any of the NITs (National Institute of Technology). I told my father to get me admitted to the college."

Two months before the Intermediate examinations, he said, he met Bachcha and "asked him if he could make me a state topper. He smiled and said my father should contact him".

His father called up Bachcha, Rahul said, and "a deal for including me among the top 10 toppers of the state was finalised at Rs 5 lakh.

Of the amount, we paid Rs 1 lakh to Bachcha in December last year. In February, Bachcha was again paid Rs 1.5 lakh and the rest of the amount was to be paid after the results".

Rahul is the second student of the four named in the FIR to be arrested. Ruby Rai, the arts "topper", was nabbed on June 25 and was granted bail on Monday. Rahul's father Sanjay Kumar, who too has been made an accused, works with the postal department in Muzaffarpur.

"His father had been arrested sometime back by the police on charges of duping people by promising them jobs," said Patna SSP and SIT chief Manu Maharaaj. "(Disgraced arts topper) Ruby Rai maintained she just wanted to do well in the exams and everything was set for her by her father in association with Bachcha. Ruby's family had made a deal of Rs 15 lakh with Bachcha. In Rahul's case, it seems it was the boy who found out about the college and told his parents that he wanted to study there and become a topper through unfair means. Rahul's family has a huge house in Muzaffarpur. The boy claims that he is an adult. However, the police want to verify it first."

Rahul said his lawyers had told him not to surrender till the court decided on his bail.

"I had filed a bail petition in the court and the hearing was to happen on Saturday this week. I was told that if the court rejected my bail, I would surrender. As far as my father is concerned, he never met Bachcha Rai and only spoke to him over the phone," he said.

The cops said Rahul was changing his location and was closely following news of the investigation.

"He seldom used his mobile phone and had logged off from Facebook," SSP Maharaaj said. "He was hiding in Motihari for some time and then came back to his home in Muzaffarpur for a while. After that, he went to his relatives' place at Azampur where he was hiding."