Jagjit Singh Chauhan, described by UK officials as a "self-styled president of the Sikh Republic of Khalistan" was among a number of suspect individuals on which the then Margaret Thatcher led government considered "further action".
"The Indian authorities have repeatedly complained about statements made in the UK by a Sikh, Dr Jagjit Singh Chauhan, self-styled 'President' of the Sikh 'Republic of Khalistan'. In June this year he 'predicted' the death of Mrs Gandhi; he has subsequently spoken of Rajiv Gandhi being a 'target'," reads a note prepared by UK foreign and home office officials in 1984.
"His remarks have drawn a sharp response from the Indian government and there is a risk of severe damage to our bilateral relations. Other Sikh extremists in the UK, some of whom have sought asylum, constitute a further threat to bilateral relations," it warns.
The documents released today also mention India's concerns over Hashim Qureshi, then Jammu and Kashmir Liberation Front leader, and his alleged involvement in the murder of Indian diplomat Ravindran Mhatre in Birmingham.