A leaked confidential police report in Germany warns of spiking refugee crime – including drug and sex offences – and a rise in radicalisation against the state.

The report says 'immigration will lead to more crime and increased police usage' to combat it.

The number of crimes – of violence, sexual, property theft and narcotic offences – will rise, says the paper of the North Rhine-Westphalian department of the interior whose 'Immigration' project involves both individual states and central government.

The document, entitled 'Challenges To And Impact On The Police', was leaked to news magazine Spiegel.

A leaked confidential police report in Germany warns of spiking refugee crime – including drug and sex offences. It come two months after the New Year's Eve sexual frenzy in Cologne (pictured) when mobs of migrant men attacked hundreds of women, robbing and molesting them as police lost control of the situation

North Rhine-Westphalia is the state in which Cologne lies, scene of the New Year's Eve sexual frenzy when mobs of immigrant men attacked hundreds of women, robbing and molesting them as police lost control of the situation.

The report spoke of an 'enormous additional burden' for police forces arising out of the refugee crisis.

In North Rhine-Westphalia last year, police had to respond 93,000 times to violence in refugee centres as 'cultural, ethnic and religious conflicts in the accommodation, the spatial narrowness, lack of privacy and the considerable consumption of alcohol triggered conflicts. Resulting consequences must be drawn.'

At the same time as predicting higher crime, the confidential paper warns of fears that attacks on migrants and their accommodation and 'right-wing agitation' may increase.

The risk-analysis paper comes as Germany continues to struggle to find a way to stem the unceasing tide of refugees across its borders.

One leading criminal specialist wrote in the paper that police must be alert to possible negative developments of objective security as well as critical aspects of the police performance of duties.'

A report from late last year by the Federal Criminal Office (BKA) painted an incomplete picture of criminality among refugees because three out of 16 federal states did not provide crime figures for the study.

Pegida organiser Lutz Bachmann (left) holds a poster during a march of the right-wing group in Leipzig in January. Germany. Pegida and other right-wing activists have been quick to latch on to the New Year's Eve sex attacks in Cologne to demand that Germany no longer accepts migrants into the country

It said that the 1.1 million migrants registered in 2015 committed over 200,000 crimes, two thirds of which involved property theft, counterfeiting and financial crimes.

About 18 per cent are so-called raw offences – injuries, threats and coercion.

Sexual attacks did not make even one per cent of the crimes and the BKA concluded: 'The vast majority of asylum seekers commit no crimes.'

The report warns that as well as rising crime in the future, Islamists are 'agitating' in asylum homes, increasing the risk of radicalisation among disaffected refugees.

It said there have been 'hundreds' of incidents in the past few months where Salafists 'have sought contact with refugees'.

Hans-Georg Maassen, chief of Germany's domestic intelligence service The Office for the Protection of the Constitution, warned last autumn that young refugees who came to Germany alone 'could be easy prey for Islamists'.