Reports in a German newspaper claim that authorities there failed to investigate thousands of asylum seekers who may have had links to war crimes.

Bild says many of the cases relate to the period around the height of the refugee crisis in 2015. The Interior Ministry denies the claims.

The newspaper says there were about 5,000 cases of asylum-seekers arriving in Germany between 2014 and early 2019 which the Federal Office for Migration and Refugees(BAMF) referred to the Federal Criminal Police Office (BKA) and the Attorney General for alleged "crimes under international law". However, fewer than 130 of the cases were investigated, claims the report.

The Interior Ministry said the "large number of referrals prevented immediate investigation of each case" but insisted that the cases were not ignored and that they were processed for use in ongoing and future investigations.

In 2015 Germany, Chancellor Merkel's open-door policy allowed almost 900,000 irregular migrants to enter the country. Many of them were escaping war-torn countries in the Middle East, Asia and Africa.

Numbers have fallen significantly since then and officials say the figure is now far below the 220,000 projected in 2018.