Some 99 per cent of migrants granted asylum in Germany are being allowed to stay permanently, according to an investigation by Die Welt published Thursday.

Though asylum is granted for a limited period of three years under the Geneva Convention, the newspaper found that 99 per cent of migrants who are granted protection are being allowed to stay in the country indefinitely.

German law entitles migrants who are reasonably well-integrated to permanent residency permits after just three years, a period which extends to just five years for migrants who fail the integration requirements — provided that they are not convicted of criminal offences.

As a result, the newspaper notes that the majority of migrants granted asylum end up as permanent residents of Germany, despite Chancellor Angela Merkel’s insistence last January that most migrants granted asylum would only be able to stay for a limited period of time.

While this process can be interrupted if a migrant’s protection status is revoked or withdrawn within the first three years, Die Welt learned that this happened in just 240 cases throughout the course of 2016.

Noting that the state granted ‘full refugee protection’ to a total of 256,136 people last year, the newspaper observed: “Only one in 1,000 refugees gets their protection status revoked.”

The Federal Office for Migration and Refugees (BAMF) told Die Welt the majority of cases in which asylum is withdrawn is when a person’s individual circumstances change, for example when unaccompanied minors reach adulthood.

Other reasons for revocation include migrants having committed criminal offences or “if asylum was granted on the basis of deception, for example, with regards to nationality”, the agency explained.

BAMF stressed, however, this does not mean “protection is denied” to people whose asylum status is withdrawn, but rather“the right to a permanent residence title is no longer applicable after a period of three years”.

Following the arrival of over a million people in Germany since Merkel’s decision to open the borders, the federal government has increased requirements for a residence permit. Before the migrant crisis, there was no need for migrants to make any efforts at integration and the period upon which the state granted permanent residence permits was always three years.

Despite the changes made to the Integration Act last Spring, permanent residence permits are granted much more quickly in Germany than other nations in Europe. Neither European nor international law requires permanent residence to ever be granted.

Migrants and asylum seekers cost Germany’s federal government €21.7 billion (£18.2 billion) in 2016, according to a Finance Ministry report published last week. The latest data is thought to reveal only around half of the true cost to German taxpayers. State and municipal governments expect to fork out around €21 billion ( (£18.1 billion) a year, rising to €30 billion (£25.9 billion) by 2020, on migrants’ cost of living.