The Catholic Church in Hong Kong said Friday that confessions by devotees to priests would remain confidential under the city's upcoming national security law.

Hong Kong is fast-tracking a homegrown national security law, following the one Beijing imposed in 2020 after quashing huge and sometimes violent pro-democracy protests.

The government bill - expected to be put to a legislature vote within days - proposes a maximum jail term of 14 years for any person who knows that someone will commit treason but fails to report it to the police.

The Catholic Diocese of Hong Kong said in a statement Friday that it "recognises that citizens have an obligation to ensure national security".

But the security law "will not alter the confidential nature of Confession", the diocese added.

The diocese had "expressed its views" on the legislation, but told AFP that it did not intend to make those views public.

UK-based activist group Hong Kong Watch earlier said the offence "directly threatens religious freedom" as it would force priests to reveal what was said in the confessional booth against their conscience.

The former British colony is a common law jurisdiction and has a legal system distinct from mainland China.

Hong Kong authorities defended the proposed criminal offence -- which used to be called "misprision of treason" -- saying that it had long existed in the city and other common law countries.

Responding to a lawmaker's question last week, Secretary for Justice Paul Lam said it would be "very difficult to create exceptions" for people like clergy and social workers regarding the offence.

The government has said the measure "has nothing to do with freedom of religion".

Hong Kong officials conducted a month-long public consultation on the security law and the subsequent legislative vetting took less than a week.

Around 390,000 of Hong Kong's 7.5 million people are Catholic, according to the diocese, and notable devotees include two former city leaders.