A new study has found that there is no conclusive evidence that Anne Frank and her family were betrayed to German occupiers during the Second World War, leading to their arrest and deportation.

One possible theory is that the Aug 4, 1944 raid that led to Anne's arrest could have been part of an investigation into illegal labour or falsified ration coupons at the canal-side house where she and other Jews hid for just over two years.

Anne kept a diary during her time in hiding in the Netherlands which was published after the war and turned her into a globally recognised symbol of Holocaust victims.

She died in the Bergen-Belsen Nazi concentration camp, in Germany, at the age of 15, shortly before it was liberated by Allied forces.

The new research, by the Anne Frank House museum in Amsterdam, reveals that there were two men who worked in the building where the teenager's family was hiding on Amsterdam's Prinsengracht canal and dealt in illegal ration cards.

They were arrested earlier in 1944, a fact mentioned in Anne's diary, and released. Such arrests were reported to an investigation division based in The Hague.