The discovery and subsequent history of the Sevso treasure deserves to be the subject of a book (Not for sale yet - the 'cursed' 14 pieces of silver worth £100m, October 17). However, it also provides a sorry commentary on the difficulties governments have in attempting to stem the illicit trade in cultural objects.

I have long tried to prod the government into taking a more proactive stance on this issue, and there has been progress in recent years - most notably in 2003 when I had the privilege of steering a private member's bill through the Lords, which resulted in the Dealing in Cultural Objects (Offences) Act being passed. As Lord Renfrew said, the Sevso treasure was probably looted and therefore "ranks as tainted goods". It could well have come within the scope of the law, but unfortunately the act only applies to objects discovered after 2003.

These 14 magnificent pieces of late Roman silverware first entered the public eye in 1990 when Sotheby's tried to sell them on behalf of the Marquis of Northampton. When Sotheby's took the treasure to New York, Lebanon, Croatia and Hungary all made claims to it.

Lebanon withdrew its claim once the Lebanese export licences were exposed as forgeries; Croatia's claim could not be substantiated; and Hungary's claim was not well presented at the New York hearing and was also dismissed. The court, however, noted that the marquis had chosen not to try to prove his title to the treasure. The marquis subsequently sued the lawyer who had advised him on the purchase and received an out-of-court settlement.

Since the US court case ended in 1993, the treasure has been hidden from public view. This is a tragedy because it is a magnificent find. But, as Roger Bland said, "under government guidelines for museums no UK museum could ever acquire or even borrow it". It is doubtful whether any other museum in the world would wish to acquire it either.

Wherever the treasure comes from - and Bonham's now states that its origin is unknown - it is difficult to see how it could have been moved from its country of origin and into Britain legally.

Unlike Lebanon and Croatia, the Hungarian government has maintained its claim and there is now a considerable body of circumstantial evidence to suggest that the treasure was indeed found in Hungary. This includes the story of its original discovery in the 1970s by Joseph Sümegh, who later died in mysterious circumstances; the name Pelso (the Latin name for Lake Balaton) on the large dish; and the fact that the National Museum in Budapest has in its collection a silver tripod found at Polgárdi in the 19th century, which looks very like another object from the hoard.

None of this evidence has been fully considered and there is an urgent need for a full examination of the origins and ownership of this treasure before determining its ultimate destination. While the treasure remains here with its status unresolved, it represents a standing challenge to the effectiveness of the measures in force in this country to combat the trade in illicit antiquities.

· Lord Redesdale is secretary of the all-party parliamentary archaeology group