An Indian man suspected by the US of involvement in an unsuccessful plot to kill a Sikh separatist on American soil has been extradited to the United States from the Czech Republic, according to the federal Bureau of Prisons website and a source familiar with the matter.

Nikhil Gupta has been accused by US federal prosecutors of plotting with an Indian government official to kill Gurpatwant Singh Pannun, a US resident who advocated for a sovereign Sikh state in northern India.

Gupta travelled to Prague from India last June and was arrested by Czech authorities. Last month, a Czech court rejected his petition to avoid being sent to the US, clearing the way for the Czech justice minister to extradite him.

An inmate search by name on the Bureau of Prisons website showed on Sunday that Gupta, 52, is being held at the Metropolitan Detention Center, Brooklyn, a federal administrative detention facility. A source familiar with the matter, who did not want to be identified, separately confirmed Gupta’s extradition and his detention in Brooklyn.

A US Justice Department spokesperson declined to comment. Gupta’s US-based lawyer, attorney Jeffrey Chabrowe, had no immediate comment. There was also no immediate comment from Czech authorities.

The discovery of assassination plots against Sikh separatists in the US and Canada has tested relations with India, seen by Western nations as a counter to China’s rising global influence. India’s government denies involvement in the plots.

Canada said in September its intelligence agencies were pursuing allegations linking India’s government to the murder of Sikh separatist leader Hardeep Singh Nijjar in June 2023 in Canada.

In November, US authorities said an Indian government official had directed the plot in the attempted murder of Pannun, who is a US and Canadian citizen. Gupta is accused of involvement in that plot.

Pannun told Reuters on Sunday that while the extradition was a welcome step, “Nikhil Gupta is just a foot soldier.”

He alleged that those who hired Gupta were senior members of the Indian government who acted on the direction of Prime Minister Narendra Modi.

India’s government has dissociated itself from the plot against Pannun, saying it was against government policy. It has said it would formally investigate security concerns raised by Washington.

New Delhi has long complained about Sikh separatist groups outside India, viewing them as security threats. The groups have kept alive the movement for Khalistan, or the demand for an independent Sikh state to be carved out of India.

Last month, Washington said it was satisfied so far with India’s moves to ensure accountability in the alleged plots, but added that many steps still needed to be taken.