Hong Kong primaries: China declares pro-democracy polls 'illegal'

City's leader announces investigation into vote that has been seen as an act of opposition to new security laws

China has declared primaries held by Hong Kong's pro-democratic parties on the weekend illegal" and the city's leader has announced an investigation, saying that the candidates' intention to vote against government legislation could break national security laws.

The primary polls, while not a formal part of Hong Kong's election process, drew an estimated 600,000 people out to vote for democracy candidates ahead of the legislative council elections scheduled for September.