Germany’s Federal Office for Migration and Refugees (BAMF) has confessed it is dealing with a “four-digit number” of migrants with declared links to the Taliban, potentially endangering neighbouring countries such as France.

According to a Der Spiegel report, German federal prosecutors are currently investigating at least 70 Afghans, although is unclear whether they are all suspected of links to the Islamist group.

Six have actually been detained, and cases are pending against several more – with prosecutor-general Peter Frank warning politicians that the authorities, which are also contending with suspected Islamic State sympathisers, have now reached “the limits of their capacity”.

Europe has been plagued by a number of mass-casualty terror attacks perpetrated by migrants in recent years. Recent examples include Uzbek asylum seeker Rakhmat Akilov, who drove a hijacked lorry into civilians on a pedestrianised street in Stockholm, and Anis Amri, a Tunisian asylum seeker who carried out a similar attack against a Christmas market in Berlin.

The revelations concerning Taliban fighters in Germany could, therefore, have an impact on the presidential run-off in neighbouring France: anti-mass migration populist Marine Le Pen is facing off against former Rothschild banker and Socialist economy minister Emmanuel Macron, and the issue of border control has been hotly contested.

Ms Le Pen has pledged to quit Schengen, the European Union agreement which eliminates border controls between most EU member-states, very early on in her presidency.

Radical Islamists have previously taken advantage of Schengen, which has been denounced as “an international passport-free zone for terrorists” by former Interpol chief Robert Noble, to attack France, often from extremist enclaves in neighbouring Belgium.

By preventing us from having national borders, the European Union condemns us to undergo #mass immigration #Marine2017 https://t.co/DxnMk2ikJH — Marine in English (@Marine2017_EN) March 10, 2017

Macron, on the other hand, is deeply committed to the EU, saying that France was a “valley of tears” before the bloc. He also accepts mass immigration will be a fact of life moving forward:

“We have entered a world of great migrations,” he said in February 2017, “and we will have more and more of it.”

Macron is also relatively laid back with respect to terrorism, describing it as “an imponderable problem”, which will be “part of our daily lives for years to come”.

Similar comments after the Nice lorry attack on Bastille Day 2016 by Macron’s former colleague, ex-prime minister Manuel Valls, proved extremely unpopular with the French public, who loudly heckled him at a crowded memorial event.

WATCH: French PM Booed After Telling People To ‘Learn To Live’ With Terrorism https://t.co/j8bgs6giDV pic.twitter.com/TdJMQXmIRS — Breitbart London (@BreitbartLondon) July 18, 2016

“Times have changed and we should learn to live with terrorism,” Valls had said following the attack, which killed 86.

The backlash against this remark is thought to have played a prominent role in terminating his own hopes of a presidential run.