Los Angeles, California - The US has charged a suspect over the murder of Sikh leader Hardeep Singh Nijjar in Canada, an incident which threw the Canada-India relationship into turmoil.

The federal indictment was unsealed in Los Angeles on Tuesday, alleging that Lawrence Bishnoi – an already-imprisoned head of an Indian crime gang – conspired with Satinderjeet Singh to order the shooting of Nijjar in 2023.

According to the charges, Bishnoi ordered the assassination from an Indian prison cell via the use of cellphones that had been smuggled into the facility.

He allegedly provided the killer with a photograph of Nijjar and multiple addresses.

Nijjar's murder in 2023 caused a massive diplomatic row between Ottawa and New Delhi, with then-Canadian Prime Minister Justin Trudeau's government pursuing allegations that Indian government agents were involved in the killing.

New Delhi had designated Nijjar – a Canadian citizen – a domestic terrorist due to his campaigning for the creation of Khalistan, an independent Sikh homeland.

In May 2024, Canadian police arrested and charged four men over the murder, but confirmed they were still pursuing possible links to the Indian government.

Indictments unsealed on Tuesday in Los Angeles, however, come as part of Operation Hard Ball, an attempt by the US to crack down on India-based transnational organized crime groups.

The charges were announced by First Assistant US Attorney for the Central District of California Bill Essayli, who said that these crime groups would no longer be tolerated.

"Transnational criminal gangs who spread fear, drugs, and violence will face the full force of justice and the weight of the federal government," Essayli said in a statement.

"Working together, law enforcement in the US, Canada, Europe, and Asia are determined to target and dismantle these criminal organizations wherever they operate. There is no safe harbor for these thugs."