Berlin (AFP) - Germany's police union on Tuesday called for the reintroduction of internal European border controls and demanded more personnel to deal with a record flood of refugees.

"From a policing point of view, a return to border controls would be the best of all measures," said Rainer Wendt, chairman of the German Police Union, in a newspaper interview.

In EU talks on the wider refugee crisis, "Germany should not take the threat of bringing back (border) controls off the table too readily," Wendt told the Passauer Neue Presse.

Europe has abolished passport controls within the so-called Schengen zone, which incorporates 22 EU members as well as Switzerland, Norway, Iceland and Liechtenstein.

However, police have stepped up spot-checks of travellers on inter-European trains, highways and flights.

Germany, the most populous EU nation, has struggled to process and accommodate a record wave of asylum-seekers fleeing war and poverty that is expected to top 500,000 this year.

The police union, which wants an extra 1,000 personnel, on Tuesday showed Interior Minister Thomas de Maiziere what it called the "catastrophic conditions" for overworked police near the German-Austrian border.

The minister during his visit pledged to send an additional 100 federal police to the southern state of Bavaria to help with the registration of migrants.

De Maiziere stressed that, while refugees who are in need of protection could seek safe haven in Germany, "those who don't need protection should quickly leave the country".

While the top country of origin for refugees to Germany so far this year has been war-torn Syria, about half have come from Balkans countries Kosovo, Albania and Serbia, whose nationals have little chance of being granted political asylum in Germany.

Wendt said that bringing back passport checks -- as Germany did temporarily while hosting a G7 summit in June -- would allow refugees to be sent back immediately to the country in which they entered the Schengen zone, where they should technically lodge their asylum request.