Anti-Islam Dutch MP Geert Wilders and his far-right Freedom Party suspended all public activities Thursday pending a probe after a police agent was arrested for leaking information about him to a Moroccan gang.

"Very disturbing news. The Freedom Party is suspending all public activities until all facts in connection with the investigation are known," Wilders said in a Tweet, as Dutch political parties gear up for crunch elections three weeks from now.

Wilders, who has courted controversy with his hardline anti-Islam, anti-immigrant stance and his incendiary insults against Moroccans and Turks, has long been under 24-hour police protection.