A real-life contemporary treasure-hunt with at the heart of it the untold story of the colourful and adventurous Duleep Singh, the last Emperor of the Sikhs.

In July 1997 the Swiss Bankers' Association, under international pressure to atone for wartime compliance with Hitler's Germany, published a list of over 1,700 'dormant accounts', untouched for over fifty years. The names were supposedly those of Jewish victims of the Holocaust, but among them was an Indian princess, 'last heard of in 1942 living in Penn, Bucks'.

Intrigued, Christy Campbell, a journalist on the Sunday Telegraph, started to search the records, and so uncovered the remarkable story of how Maharajah Duleep Singh, the last Emperor of the Sikhs, was made by the British - as a nine-year-old in 1849 - to sign away his kingdom of the Punjab and give Queen Victoria the Koh-i-Noor diamond (the most celebrated diamond in the world, and the jewel in Britain's Crown).

Duleep Singh, a virtual prisoner of Queen Victoria in England, began to dream of regaining his kingdom, and so embarked on a series of adventures (involving Russia and the 'Great Game' of Central Asia) before finally begging Victoria's forgiveness. He had six children and died in 1893. What he didn't know was that different factions in Russia were making use of him - and the British secret service were doing likewise.

Today the Sikhs still claim their inheritance, including the Koh-i-Noor and the now-divided Punjab. When the Maharajah's box is opened in summer 1999 it is likely to reveal further secrets.

Christy Campbell was a publisher's editor before turning freelance writer. He has written for the Sunday Telegraph since 1990 when he joined as Defence Correspondent covering the Gulf War. He has made a speciality of 'forensic historical investigations' and produced a series of special supplements for the Sunday Telegraph on 20th-century history. He has also written a number of non-fiction books on World War II and broadcast on radio and television.