The alleged mastermind of the Parliament security breach, Lalit Jha, was on Friday sent by a Delhi court to police custody for seven days.
The key accused will be questioned by the Delhi Police Special Cell while the other four accused in the case nabbed on the day they stormed Parliament were sent to police custody on Thursday.
Jha, who was on the run ever since the incident took place, is said to have surrendered before the Delhi Police on Thursday evening leading to his arrest later, the sources said.
It is said Jha, who hails from Bihar, used to work in Kolkata.
Meanwhile, two more people have been detained by the police in this connection, according to the sources.
The four accused held on Wednesday, including Sagar Sharma, who jumped into the LS hall and is from Lucknow, Manoranjan D, also nabbed from inside of the Lok Sabha chamber by the MPs and staff, Neelam who is from Haryana and was held from outside the Parliament complex near the Transport Bhawan and Amol Shinde, who was also nabbed along with Neelam outside the parliament complex.
The investigation into the case registered under the Unlawful Activities (Prevention) Act (UAPA) is being conducted by the Delhi police special cell. The FIR charged Sagar Sharma and Manoranjan D with using creative colour smoke inside the Lok Sabha. It also mentions how they sneaked the smoke cans inside the House in a special cavity inside their shoes.
The duo, Neelam and Amol, who were nabbed from outside the Parliament complex on the same day, were also found to be associated with Sagar Sharma and Manoranjan.
Forensic and mobile crime teams inspected the spots of occurrence and collected the exhibits.
Along with various sections of the Indian Penal Code, sections 16 and 18 of the UAPA were included in the case.