Germany is secretly expecting to receive 1.5million migrants this year - 700,000 more than it has publicly stated, according to previously unseen documents.

Bild newspaper, quoting a confidential document, said authorities were expecting to receive 920,000 new arrivals in the coming three months alone - bringing the country's total this year to 1.5million.

The figures are a departure from much lower estimates German officials have publicly stated, after having relaxed rules which mean it is not sending Syrians back to other EU countries.

Police detain a group of asylum-seekers at Munch rail station after they arrived in the country from Hungary

Hundreds of migrants queue outside the Berlin Office of Health and Social Affairs as they wait for their asylum registration

The document stated: 'The migratory pressure will increase. For the fourth quarter, we expect between 7,000 and 10,000 illegal entries a day.

'The significant number of asylum-seekers risks becoming an extreme burden for the regions and communes,' added the document.

The newspaper also quoted the document estimating that each asylum-seeker who successfully obtained refugee status could bring on average 'four to eight' family members to Germany.

On the basis of the preliminary forecast of 920,000 migrants, some '7.36 million people' could therefore have the right to move to Germany due to family ties.

Interior ministry spokesman Harald Neymanns would not confirm the figures, noting however that the onset of winter could slow the surge in arrivals - as shown in previous years.

'We are still expecting the migration pressure to drop in the winter months,' he said.

Government spokesman Georg Streiter said he was not aware of the document's existence.

Chancellor Angela Merkel has been lauded worldwide for her decision to open Germany's doors to refugees fleeing war and misery.