A record 55,000 migrants left Germany voluntarily this year, which is more than twice the figure deported by the authorities.

The data released by the country's Office for Migration and Refugees (BAMF), showed that most of the migrants went back to the Western Balkans.

More than a million migrants entered Germany in 2015, and this year the country deported 25,000 people.

A record 55,000 migrants left Germany voluntarily this year, which is more than twice the figure deported by the authorities (file photo)

Around 15,000 of those who left on their own accord returned to Albania and 3,200 to Afghanistan.

German chancellor Angela Merkel has vowed to take a harder line on migrants after her open-door policy was slammed by critics, and this year Germany refused entry to 20,000 at its external borders, according to Sueddeutsche Zeitung (SZ).

A new €150m programme is to be launched in the New Year to help them reintegrate in their home countries such as Morocco, Tunisia, Nigeria, Kosovo, Serbia and Albania, SZ reports.

The largest groups seeking asylum in Germany this year were Syrians, making up 38 percent of the migrant population.

Germany has been rocked by terror this year, heaping pressure on chancellor Angela Merkel's open-door immigration policy.

A bloody week of violence that rocked Germany began on July 18 when Pakistani teenager Riaz Khan Ahmadzai, 17, posing as an Afghan refugee, hacked at passengers on a train in Wurzburg with an axe, wounding five.

German Chancellor Angela Merkel appears to have a lot on her mind as she awaits the arrival of EU Council President Donald Tusk outside the Federal chancellery for talks in the wake of the Brexit vote, in Berlin, Germany

He was shot dead by police.

Four days later mentally unstable German-Iranian teenager Ali Sonboly shot nine people dead during a rampage through a shopping centre in Munich before taking his own life.

Sonboly claimed he was taking revenge for being bullied at school with no political motive to the murderous rampage.

Earlier that month, a suspected ISIS airport bomb plotter hanged himself in a German prison after being arrested following a manhunt.

Syrian national Jaber al-Bakr, 22, was found hanged in his cell in Leipzig, eastern Germany on Wednesday evening - having reportedly used his own t-shirt - and was taken away overnight.

He was detained on Sunday after three days on the run following a tip-off that he may have been looking to team up with associates in Leipzig.

Al-Bakr had built 'a virtual bomb-making lab' in a flat in Chemnitz and was thought to have planned an attack against either one of Berlin's two airports or a transport hub in his home state of Saxony, security sources said.

Chemnitz was on lockdown for hours when police raided his flat but failed to seize him before he was captured by fellow Syrian nationals who tied him up and handed him over to the authorities.

And on Monday, December 19, Tunisian ISIS fanatic Anis Amri hijacked a 35-tonne truck and ploughed it into a Christmas market in Berlin, killing 12 people.