Four assault rifles used in the Paris terrorist attacks were reportedly bought from a German arms dealer on an underground Internet marketplace.

The ISIS-affiliated terrorists allegedly ordered two Chinese-made AK47 assault rifles and two Zastava M70s, made in Yugoslavia in the early 1990s, according to documents submitted to the Stuttgart prosecutor's office seen by German newspaper Bild-Zeitung.

The weapons are thought to have been sold to a Paris buyer of "Arab descent" on Nov. 7 on a hidden section of the Internet known as the Darknet, in a store called "DW Guns," according to AFP.

"French investigators believe that the weapons were allegedly used in the attacks in Paris," said Bild, according to AFP.

German authorities in the southern city of Stuttgart confirmed on Friday they had arrested a 34-year-old man named Sascha W. on Tuesday on suspicion of arms dealing but would not confirm whether he supplied the Paris attackers with the four guns.

"I can confirm that a man is in custody on suspicion of arms trading," a spokesman for the prosecutor in the state of Baden-Wuerttemberg told Reuters.

The man is reportedly accused of rigging legal starter pistols to fire live ammunition and selling them on the Darknet, but emails on his smartphone indicate he was also in touch with an "Arab in Paris," according to Fox News.

Police say he was involved in at least eight cases of illegal arms trafficking from Aug. 14 to Nov. 18, 2015, reports RT.