The Catholic Church in Australia says new laws aimed at curbing interference by foreign states could force bishops, priests and nuns to publicly declare that they are agents of the Vatican.

The laws, which followed concerns about China’s efforts to meddle in Australian politics and universities, require anyone acting for a foreign power to reveal their status or face criminal charges.

But Catholic leaders say the measures will “silence” members of the Church involved in advocacy and could require them to register as agents of the Pope or the Vatican.

"Catholics are followers of Jesus Christ, we are not agents of a foreign government,” Catholic Bishop Robert McGuckin, from Toowoomba in Queensland, told a parliamentary inquiry.

"The Catholic Church in Australia is made up of millions of Australian citizens who practice their faith, and they are not beholden to a foreign power.”

He added: "It seems that every Catholic involved in advocacy may need to register and report. Given Catholics make up more than the 20 per cent of the population of Australia … we think that's a lot of registrations."