A Belgian couple from Antwerp held last Saturday on suspicion of plotting a terror attack in France may have been in the grand duchy prior to their arrest. Germany’s Bild Zeitung claims that a German, who was arrested in Germany, met the Iranian born couple in Luxembourg to hand over the half a kilogram of homemade explosives that was found in the car they were driving.

Sources say the couple, 38-year-old man and the 33-year-old woman, was planning to use the explosives in an attack on a demonstration in Villepinte outside of Paris, which was attended by around 25,000 supporters of the Mujahedin-e Khalq, which opposes the Iranian regime.

Bild reports that the German suspect is likely to be extradited to Belgium. Meanwhile, the third ranked counsel at the Iranian embassy in Vienna was arrested after a routine check on the German motorway, after it emerged that he was working for the Iranian secret service and traces of explosives were found in his car. German authorities are believed to have been tipped off by their Belgian counterparts after questioning the Antwerp couple.

The Luxembourg prosecutor's office confirmed on Tuesday that the Belgian authorities had requested assistance in the matter. It says close contact was maintained between the authorities in both countries during the operation, but the prosecutor also stresses that at no point was there any risk or danger to the Luxembourg populace. But the office would not supply any further information on the case.

Some reports say that Iran's Foreign Minister Mohammad Javad Zarif has already called the uncovering of the terror attack a “false flag ploy.”