The closing submissions in a national security trial against Hong Kong pro-democracy businessman Jimmy Lai were delayed on Friday after his lawyer said he had suffered heart palpitations.

A Hong Kong court on Friday began hearing closing arguments in the national security trial of pro-democracy media tycoon Jimmy Lai, following a one-day delay because of bad weather.The 77-year-old founder of the Apple Daily newspaper is charged with foreign collusion under Hong Kong's national security law,

The Hong Kong pro-democracy tycoon has been charged under a Beijing-backed law critics say has been used to crack down on dissent.