The ongoing polygraph and narco-analysis tests on the Parliament security breach accused was completed on Friday, an official said.

The five of the six accused -- Sagar Sharma, Manoranjan D, Amol Shinde, Lalit Jha and Mahesh Kumawat -- were taken for polygraph tests to Ahmedabad on December 8.

"The polygraph tests of all five were conducted at the Forensic Science Laboratory in Gandhinagar," an officer said, adding Sagar and Manoranjan had to undergo additional naro-analysis and brain mapping tests.

The investigators have tried to ascertain the actual reason behind their act of breaching the Parliament security, the officer said.

The Delhi Police had earlier moved the court seeking permission to conduct the polygraph test of all the accused. Neelam Azad, the sixth accused, did not give her consent for the test before the court.

The officials said as the tests were completed, the accused may be brought back to Delhi as their eight-day police custody is ending on Saturday. In a major security breach on the anniversary of the 2001 Parliament terror attack on December 13, two people -- Sagar Sharma and Manoranjan D -- jumped into the Lok Sabha chamber from the public gallery during the Zero Hour, released yellow gas from canisters and shouted slogans before being overpowered by the MPs.

Around the same time, two other accused -- Shinde and Azad -- also sprayed coloured gas from canisters while shouting "tanashahi nahi chalegi" outside the Parliament premises.

A narco-analysis test involves the intravenous administration of a drug that causes the subject to enter into a stage of anesthesia during which the person becomes less inhibited and is more likely to divulge information, which would usually not be revealed in the conscious state.

Brain mapping, which is also called neuro mapping technique, analyses the brain’s responses to images or words related to the crime.

In a polygraph test, efforts are made to ascertain whether the subject is lying or not by tracking breathing rate, blood pressure, perspiration and heart rate, while the person is asked various questions.

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