Former JDU leader Usha Sinha was the mastermind of the Intermediate exam scam, police said today.

Sinha and her husband Lalkeshwar Prasad Singh were sent to judicial custody today, until July 4. They were produced before special vigilance judge Raghwendra Kumar Singh today after the special investigation team (SIT) arrested the couple from Varanasi in Uttar Pradesh on Monday. Five more people involved in the topper scam were also produced in court.

Cops told The Telegraph that Lalkeshwar used to work under the directions of his wife who in turn used to deal with Bachcha Rai, the director-cum-principal of Vaishali's Vishun Roy College.

"Usha Sinha's role in the scam appears to be the most prominent of all," an officer associated with the investigation said. "She is the ring leader and Lalkeshwar, the former chairman of the Bihar School Examination Board, used to follow her directions. She was always in touch with Bachcha and would preside over all the dealings."

The police have requested the court for a remand of Lalkeshwar and Sinha, Patna senior superintendent of police Manu Maharaaj said. He added that sections under the Prevention Of Corruption Act, 1988, have been included in the FIR against the duo.

On Monday, the court of the chief judicial magistrate transferred the case to the special vigilance court after the new sections were included.

"The police have sufficient evidence against Lalkeshwar and Sinha. Four days before the Intermediate science results were announced (May 10), Lalkeshwar had gone to the Rajendra Nagar Government Boys Senior Secondary School and collected the answer sheets of at least four of the toppers," Maharaaj, who heads the SIT, said. "Lalkeshwar's call record details from that dayprove that he was in the school. The police are also on the lookout for a person in Nalanda, who was appointed at the college by Lalkeshwar and Sinha in return of money. The police have quite a few examples of people with little or no academic background being made teachers and even principals. Many of them are absconding now."

Another cop claimed Lalkeshwar's personal assistant Anil Thakur has told the police after his arrest that Bachcha had taken Rs 4 lakh from a person with the promise that the candidate would clear the Teacher Eligibility Test (TET).

"Bachcha paid Rs 1 lakh of the money taken to Sinha. The police have recovered written answer sheets, blank admit cards from his residence. There is a strong suspicion that Sinha, Lalkeshwar and Bachcha were involved in a scandal involving the TET as well," the officer said.

The police also said some of the Intermediate toppers did not even appear in the examination.

"Going by the CCTV footage at GA Inter School in Vaishali, the examination centre for Vishun Roy College, some of the toppers didn't even go to the centre to write their papers," an officer said. "The total marks of one of the papers was 50 and a student was given 51 marks. The anomaly was noticed at the right time and the tabulation sheet could not be tampered."

The team involved in the arrest of Lalkeshwar and his wife said on many occasions, the former school board chairman pleaded he had cardiac problems that were getting worse.

"A doctor has been deputed to check on him regularly. He was acting the same way in court too," an SIT member said.

Patna zonal inspector-general N.H. Khan said the absconding toppers and their parents wouldn't be given a long rope now.

"They have been served notices but have not turned up. The police will now take stern legal steps against them," he said.