Australian paedophiles will have their passports cancelled and right to travel overseas revoked under "world first" laws announced by the Turnbull government.

The crackdown, which follows high-profile cases of child exploitation in south-east Asia and fervent campaigning by anti-paedophile senator Derryn Hinch, will affect the more than 20,000 people on the National Child Offender Register.

"This the strongest crackdown on child sex tourism ever. No country has ever taken such decisive action to stop its citizens from going overseas, often to vulnerable countries, to abuse kids," Justice Minister Michael Keenan said on Tuesday.