Britain despatched an undercover diplomat on a covert mission to the Bahamas to convince the deposed Shah of Iran not to seek to settle in the UK.
The revelation comes in official archive documents made public 30 years after they were written.
The 1979 papers reveal that the British government was very concerned that Mohammad Reza Shah Pahlavi, then in exile, would seek to live in England.
But Prime Minister Margaret Thatcher was upset she could not help the Shah.
