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Nikhil Gupta, 54, pleaded guilty to murder-for-hire, conspiracy to commit murder-for-hire, and conspiracy to commit money laundering in a New York courtroom on Friday.Jane Rosenberg/Reuters

An Indian man charged with orchestrating a foiled plot to kill a Sikh separatist in New York City has pleaded guilty, in a case connected to the investigation into the killing of Canadian Hardeep Singh Nijjar.

Nikhil Gupta, 54, pleaded guilty to murder-for-hire, conspiracy to commit murder-for-hire and conspiracy to commit money laundering in a New York courtroom Friday, convictions that mean he’s facing up to 40 years in prison.

U.S. prosecutors allege that Mr. Gupta was involved in a larger conspiracy, directed by the Indian government, to kill multiple Sikh separatists in North America as part of a violent campaign against leaders of a movement to create an independent state in northeastern India known as Khalistan. American prosecutors have alleged that Mr. Nijjar, who was gunned down outside a Sikh temple in Surrey, B.C., on June 18, 2023, was also a target.

Prosecutors say that in May of 2023, Mr. Gupta was recruited by an agent of India’s foreign intelligence service, the Research and Analysis Wing, to help broker a deal to pay a hitman US$100,000 to murder Gurpatwant Singh Pannun, a lawyer and outspoken critic of the Indian government. Mr. Gupta was arrested on June 30, 2023, in the Czech Republic, also known as Czechia, and extradited to the U.S.

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Lawyers for Mr. Gupta, jailed in Brooklyn since his extradition in June, 2024, were not immediately available for comment. He had pleaded not guilty immediately after his extradition.

In a statement, the U.S. Attorney’s Office for the Southern District of New York said Mr. Gupta’s role in the plot to kill the New York-based lawyer was linked to the assassination of Mr. Nijjar. Just hours after that killing, according to the indictment against Mr. Gupta, he was sent a video of Mr. Nijjar’s dead body – which he shared with an undercover officer posing as a hitman, saying Mr. Nijjar “was also the target” and “we have so many targets.”

The Indian government agent who allegedly sent him that video, Vikash Yadav, is co-accused in the murder plot. Mr. Yadav is believed to be in India, where he is facing separate criminal prosecution for his role in an alleged kidnapping in that country.

India’s alleged role in multiple plots to kill Sikh activists has strained relations between Canada and New Delhi. In October, 2023, then-prime-minister Justin Trudeau told Parliament that Canada had “clear and compelling evidence” showing Indian government involvement in violence and surveillance against South Asian Canadians, stemming from the investigation into Mr. Nijjar’s killing.

Four people, all Indian nationals, have been charged in his slaying. In October, 2024, Ottawa expelled six Indian diplomats, in a decision that was explicitly tied to the Nijjar investigation.

New Delhi, meanwhile, has dismissed Mr. Yadav as a rogue operator, and consistently denied any involvement in the plots to kill Mr. Nijjar and Mr. Pannun. The RCMP and Global Affairs Canada did not immediately respond to a request for comment.

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U.S. prosecutors said Mr. Gupta was an international narcotics and weapons trafficker who agreed to co-ordinate the assassination plot in exchange for having criminal prosecutions against him dropped in India. Some of the evidence in the case was obtained through electronic communications with Mr. Yadav found on his phone after it was seized.

The U.S. Attorney’s Office said the murder conspiracy was foiled when Mr. Gupta contacted a man that he believed to be a criminal associate, but who was in fact a confidential source working with the U.S. Drug Enforcement Administration. On June 9, 2023, Mr. Yadav and Mr. Gupta, both working from India, arranged for an associate to deliver $15,000 in cash to an undercover officer as an advance payment for the murder, according to the indictment.

“At the direction and co-ordination of an Indian government employee, Nikhil Gupta plotted to assassinate a United States citizen on American soil, facilitating a foreign adversary’s unlawful effort to silence a vocal critic of the Indian government,” said James C. Barnacle, Jr., an FBI assistant director.

Mr. Pannun, the target of the foiled plot, said Mr. Gupta is merely a “foot soldier” and that the Indian government must be held accountable.

The lawyer said the case clearly shows the killing of Mr. Nijjar was part of a broader effort to eliminate Khalistan activists, and called on U.S. officials to prosecute those who orchestrated that campaign.