Then British Prime Minister Margaret Thatcher's government believed that "illicit heroin movement from India" was at an "all-time peak" and wanted her Indian counterpart Rajiv Gandhi to agree to two British Drug Liaison Officers (DLOs) to be appointed in India.
However, Mr Gandhi resisted until India had received information of its own on offenders seeking refuge in the UK, according to newly declassified documents in the National Archives.
In contrast, Pakistan under President Zia-ul-Haq seemed more receptive to Britain's requests with DLOs placed in Karachi and Islamabad happy with "effective steps to tackle the problem of heroin production".
"The evidence was that Pakistan was getting on top of the drug production problem," a letter to Downing Street dated December 4, 1985, noted following a visit by then UK health minister David Mellor to Pakistan.
"It went on to warn of the problem shifting to India, saying "Mr Mellor believed that, "as drug controls were increased in Pakistan, and particularly at Karachi Airport, much of the traffic was now taking the land route to India".
"This would inevitably have an impact on the extent of heroin used and production in India itself. India might replace Afghanistan and Pakistan as the major world supplier," according to the now released cabinet file.
Mr Mellor was concerned about delays in securing India's agreement to the secondment of two Customs officers.
Following a telegram from the then British Prime Minister questioning the reason for the delay, Mr Gandhi responded, "I feel that there is a communication gap somewhere. We are determined to combat the drug menace with every resource at our command. We had readily agreed, in principle, to British drug liaison presence in India."
"We have an equally pressing problem in relation to conomic and commercial offenders, who operate from or seek foreign sanctuaries. Our Parliament and people continue to be exercised on what is perceived to be lack of adequate action against such offenders," Mr Gandhi wrote.
Britain finally got its way and Hartley Booth, an adviser to Mrs Thatcher, confirmed the success in a memo dated November 28, 1986, "After 31 approaches from officials and FCO (Foreign & Commonwealth Office) ministers during the last 15 months, India relented on November 20 and accepted the appointment of two drugs liaison officers from the United Kingdom to India".
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