A new bill, which will allow art looted by the Nazis and found in British museums to be returned to its original owners, has passed into law today.

Labour’s Andrew Dismore, MP for Hendon, first sponsored the Holocaust (Stolen Art) Restitution Act, which has now been given Royal Assent.

He said: “It shows what could be achieved by a determined backbencher: by rolling out my sleeping bag and sleeping on the floor of the Public Bill Office overnight, I was able to become the first in the queue to apply for Second Readings after the balloted Bills, and this tactic paid off.

"While I do not envisage the Act having to be used very frequently, this is an important moral step, to ensure that we can close yet a further chapter on the appalling crimes of the Holocaust.”

Before the law was passed, the government’s Spoliation Panel would recommend artworks and museum piece which should be returned to their original owners, but museums did not have the legal power to carry out the recommendations of the panel.

The new law will allow heirs to have a choice whether to have their property returned to them, or to be given compensation.

Estimates suggest around 20 looted items are in British museums, but the number could be far greater.

Cupid Complaining to Venus, by Lucas Cranach, dated 1525 which is now in the National Gallery, could be one of such artwork. It was once part of Adolf Hitler's private collection but its former ownership is a mystery.

Lord Janner, who supported the Bill during its passage through the House of Lords, said: “The issue of restitution is of vital importance to me. My entire family in Lithuania and Latvia were murdered by the Nazis, the killers stole all of their property. This bill will at least give families of some Holocaust victims the power to reclaim some of their family property, which is in Britain.”

Culture Minister Margaret Hodge said: “This is a wonderful day, both for Andrew and those who will benefit from this change in legislation. For too long, families who had heirlooms stolen from them by the Nazis were unable to reclaim them, although they were the rightful owners.

“This new Act will restore the possibility for families who suffered so terribly during the Nazi era, to get some justice by getting back their heirlooms.”

Jon Benjamin, chief executive of the Board of Deputies, commented: “We are extremely grateful for the invaluable assistance of officials and politicians at DCMS, and in Parliament, in bringing about this piece of legislation and would like particularly to acknowledge Andrew Dismore’s role in the Commons and Lord Janner’s in the Lords.”