India has failed to secure the extradition of a UK-based activist it claimed was a key player in a plot by Sikh extremists to murder the chief minister of India’s Punjab region. Kuldeep Singh was arrested in the UK in 2019 and accused of conspiring with members of the Khalistan Zindabad Force to carry out gun and bomb attacks targeting the region’s leaders as part of the group’s aim to create a Sikh homeland. He was said by the Indian authorities to be a UK-based middleman with contacts in India, Pakistan and Belgium for the organisation, which in 2005 was listed as a terrorist organisation by the UK. Indian prosecutors said the group was stockpiling weapons as part of a plan to attack Punjab’s chief minister, his deputy and other leaders. The attacks were never carried out and India’s case for extradition relied on police interviews with two other accused men who named Mr Singh after they were arrested in India when the plot unravelled. A British judge earlier this year ruled that the evidence of two men accused of the same crime could not be used to justify Mr Singh’s extradition. Two judges dismissed an appeal by the Indian authorities, in a ruling by the High Court in London published on Thursday. The court was told that Mr Singh entered the UK illegally in 2005 and stayed under the radar for more than eight years before embarking on a series of unsuccessful claims to remain in Britain. He was awaiting the result of an asylum claim last year, according to court documents. The failure is the latest in a long string of failures by the Indian authorities that has allowed the UK to become a key destination of choice for Indian fugitives from justice. The Indian authorities were successful in persuading British judges to extradite high-profile businessmen – such as jeweller Nirav Modi and airline tycoon Vijay Mallya. But those cases – which are subject to legal challenges – have obscured three decades of predominantly failed efforts since an agreement was signed in 1992. “The judgment in the Kuldeep Singh extradition case shows profound lack of professionalism on the part of investigating agencies in India,” said Danish Khan, a historian and journalist in London, who has written a book charting India’s unsuccessful extradition efforts. “Singh faced very serious charges of involvement in terrorism and planning to assassinate senior politicians, but the evidence produced in the English courts were just summaries of what co-accused told a police officer.” The armed fight for a state of Khalistan – which its advocates say would be formed from the Punjab region straddling the border between India and Pakistan – reached its height in the 1980s. It culminated in the assassination of prime minister Indira Gandhi by two of her Sikh bodyguards in reprisal for the storming by Indian troops of the Golden Temple of Amritsar, the most holy place for Sikhs. Thousands were killed in the subsequent crackdown.