The US says it foiled an alleged plot to assassinate an American citizen in New York who advocated for a Sikh separatist state.
Nikhil Gupta, an Indian national, was charged on Wednesday. He was directed by an Indian government employee, according to the indictment.
He has been charged with murder-for-hire over the plot, which prosecutors said was orchestrated from India.
The alleged target was not named in the court documents.
The Indian government earlier said it had started an investigation of security concerns aired by the US in relation to the plot. After the indictment was unsealed, it reiterated its intention and said relevant departments were already examining the issue.
The White House said it had raised the alleged plot with the Indian government at the most senior levels. It added that Indian officials responded with “surprise and concern”.
According to the indictment, Mr Gupta was involved in international narcotics and weapons trafficking before he was allegedly recruited by an Indian government official in May to pursue the assassination of the target.
It alleges Mr Gupta was directed by the official to contact an associate in the US about potential assassination plans. Mr Gupta, it says, had intended to meet a hitman who could murder his target in New York City.
Instead, court documents say, the source introduced him to an undercover law enforcement officer who said he would assassinate the target for $100,000 (£79,000).
Mr Gupta paid $15,000 upfront via an associate on 9 June, the indictment alleges.
Authorities in the Czech Republic arrested Mr Gupta on 30 June shortly after US prosecutors released an initial indictment against him. They are still detaining him at the US’s request, according to court documents.
Although the target of the alleged assassination plot was not named in the documents, American authorities emphasised that he was a US leader in a Sikh separatist group.
Sikhs are a religious minority that make up about 2% of India’s population. Some groups have long called for a separate homeland for Sikhs.
The Indian government has often reacted sharply to demands by Sikh separatists in Western countries for Khalistan, or a separate homeland.