A pedophile was arrested at Sydney Airport on Wednesday as strict new laws on sex offenders went into effect, local media reported. The Australian government is aiming to crack down on the number of citizens flying to southeast Asia for child sex tourism.

"Australia has up to 20,000 registered child sex offenders who have served their sentences, but are subject to reporting obligations that help protect the community," Foreign Minister Julie Bishop told reporters at the airport.

She added that about 800 registered child sex offenders from Australia went abroad last year, and of those about 40 percent did not inform the authorities of their travel plans.

The new laws allow the Foreign Ministry to cancel or deny Australian passports, as well as demand the surrender of a foreign passport.

The man arrested on Wednesday morning was caught by a new "smart gate" feature that recognizes the passport numbers of convicted pedophiles.

"For too long, these predators have traveled overseas undetected, including to countries where weaker laws mean they have opportunities to commit heinous crimes," Bishop was quoted by the New York Times as saying.

Toughest laws on the books

Justice Minister Michael Keenan has described the new measures as the toughest in the world.

"We will ensure that we will have a presumption against bail, we will have a presumption against parole, we will ensure that the most serious child sex offenders serve a minimum period of time in prison."

With increasingly cheap flights on offer from Australia to countries with fewer protections for children, such as Malaysia, Indonesia and Thailand, child sex tourism has been on the rise.

Punishment for child sex offenders has become a major theme in Australian politics of late, with the ruling Liberal Party heavily in favor of mandatory minimum jail terms for convicted pedophiles. The opposition Labor Party, however, believes that mandatory minimums will make sex offenders less likely to give up the names of ring leaders.