Hong Kong media mogul Jimmy Lai, one of the city's most vocal Beijing critics, was arrested on Monday under a new national security law, news agency AFP has reported. Lai has been charged with colluding with foreign forces. A close aide of Lai told AFP that he was from his home early Monday morning. Other members of Lai's media group had also been arrested, reports said. Jimmy Lai owns the Apple Daily newspaper and Next Magazine, two outlets unapologetically pro-democracy and critical of Beijing. Chinese media has often described the pro-democracy tycoon as a "traitor".