A court in Hong Kong adjourned a national security trial hearing of media mogul Jimmy Lai on Friday due to concerns about his health after his defense said he had been experiencing heart palpatations.

Lai, 77, has pleaded not guilty to charges under Hong Kong's national security law of conspiracy to collude with foreign forces, as well as to a separate charge of conspiracy to publish seditious material. He has been held in solitary confinement for more than 1,500 days since December 2020.

Hong Kong postponed media mogul Jimmy Lai's trial on Friday, awaiting a heart monitoring device -- the second delay this week to the democracy campaigner's case.The Hong Kong government said Wednesday it "strongly disapproved and rejected the slanderous remarks made by external forces" regarding Lai's case.