The NIA will move court next week to seek permission for the lie detector test. Officials said that for the test to be conducted, Mr. Singh has to give his concurrence first. The official did not explain whether Mr. Singh has agreed for the tests.

The NIA has questioned him continuously for five days but is still not convinced with his replies.

"There are several contradictions in his version and we need to ascertain the truth. Though he has expressed innocence, the sequence of events narrated by him don't add up," said a senior NIA official.

Mr. Singh, who is also one of the prime witnesses in the case, had claimed that he was abducted by terrorists in the early hours on January 1, 2016, when he was reportedly returning from a mazar (religious place) in a village in the border district of Gurdaspur. Mr. Singh was accompanied by his jeweller friend Rajesh Verma and his cook Madan Gopal.