India on Thursday rejected as “unwarranted and unsubstantiated imputations” a lawsuit filed by Khalistan separatist Gurpatwant Singh Pannun against the government, claiming that the government had attempted to assassinate him.

“As we have said earlier, these are completely unwarranted and unsubstantiated imputations,” Foreign Secretary Vikram Misri told the media, dismissing the allegations.

“Now that this particular case has been lodged, it doesn’t change our views about the underlying situation. I would only invite your attention to the person behind this particular case whose antecedents are well known,” the official added, The Indian Express reported.

He stressed that the group led by Pannun is an “unlawful organisation” under the Unlawful Activities Prevention Act of 1967 due to its involvement in anti-national activities that threaten India’s sovereignty.

On Tuesday, Pannun filed a civil lawsuit in the U.S. District Court for the Southern District of New York. He aims to hold the Indian government accountable for its alleged role in the death of Hardeep Singh Nijjar in Surrey, British Columbia, last year, as well as for a plot against Pannun that followed, according to a CBC report.

“The lawsuit filed by Pannun says gunmen in shot Nijjar 34 times ‘at point blank range before fleeing,’ and a video of Nijjar’s ‘bloody body’ was sent to Nikhil Gupta ‘as a message to move forward’ with the murder plot against Pannun,” the report further said.

Nikhil Gupta, an Indian national, has been accused of involvement in a murder-for-hire plot against Pannun on U.S. soil. He was arrested in the Czech Republic last year at the request of the U.S. government.