The man who was killed after plowing a car filled with guns into a police van on the Champs-Elysées had a permit to carry arms despite being on France’s terror watch list, officials said.

Adam Dzaziri, 31, had at least nine weapons — including two pistols and a Kalashnikov-type assault rifle — in his home in the Paris suburb of Argenteuil, a source close to the probe told the Telegraph of the UK.

Dzaziri was carrying in his car an assault rifle, two handguns, ammo and two large gas canisters, two police sources and the judicial official told the paper.

Prime Minister Edouard Philippe expressed his alarm that Dzaziri was able to have a weapons permit despite being on a jihadist watch list.

“What I know at this stage is that the first weapons permit was given before this individual was flagged up,” he told BFM-TV and RMC radio Tuesday.

He said “nobody can be satisfied — and certainly not me” that Dzaziri had still been able to carry lethal weapons.

Asked to explain why Dzaziri’s permit wasn’t revoked, Philippe said that “if you take away a permit from someone who is the subject of surveillance or being monitored, he will quickly understand why it has been taken away. … It’s a difficult decision.”

Four suspects were detained overnight in the anti-terrorism probe into Monday’s attack, the Paris prosecutor’s office announced.

Djaziri set off an explosion when he drove his car into the police van, authorities said.

Gendarmes jumped out of their vehicle, ran to his car, smashed its windows and pulled him out in an apparent attempt to save him, according to witnesses, the Telegraph reported.

No one else was injured, and the Champs-Elysees reopened overnight.