German police are scrambling to discover whether they inadvertently prevented another Islamist from joining the Paris massacre, after they arrested a man driving with a significant cache of weapons heading to Paris.

The arrest took place on Thursday the 5th, when during a routine inspection police investigated a car driven by a 51-year-old Montenegrin man as he drove west on the major Autobahn-8 road, shortly after crossing the border from Austria. When officers found two handguns and a grenade under the bonnet of the car, the search intensified, and they soon discovered a significant hidden arsenal.

Also secreted about the car behind panels were eight Kalashnikov assault rifles with ammunition, several handguns, two hand grenades, and 200 grams of TNT, reports Bayerischer Rundfunk.

The car wasn’t only being driven west. Bavarian interior minister Joachim Herrmann has confirmed that based on “the data of the man’s [GPS] navigation system, and his cell phone there is strong evidence that the man wanted to go to France”. German media have reported he specifically had Paris programmed into his sat-nav.

The Bavarian prime minister Horst Seehofer confirmed German security services believe the arrested individual may have been related to the terror cell who killed over 120 across Paris on Friday evening.

From the moment he was arrested the suspect has maintained total silence and hasn’t even taken a lawyer, reports Focus.de. German police will now be under pressure if it transpires they failed to gather intelligence from the suspect that could have helped French terror police foil last night’s attacks in Paris.

Austrian paper Die Kronen Zeitung reports the very foundations of the European free movement Schengen area will be shaken by the arrest. The suspect drove 500 miles from the Balkans, crossed the European Union’s frontier into the Schengen zone and then drove another 300 miles within the EU without being detected.

The shocking revelation comes at a time where weapons, and particularly grenades flow freely from the Balkans into Western Europe and nations across the continent are under unprecedented pressure to close their borders in the face of the migrant crisis, and Islamist terrorism.