SYDNEY (AFP) - A 16-year-old charged with preparing a terror attack linked to Anzac Day commemorations in Australia pleaded not guilty Tuesday (April 26), reports said, as it emerged he had been in an intensive deradicalisation programme.

The boy, who cannot be named, did not appear in Parramatta Children's Court in Sydney and the plea was made through his lawyer Zemarai Khatiz, the Australian Broadcasting Corporation said.

The teen has been charged with one count of acting in preparation for, or planning, a terrorist act by allegedly attempting to buy a gun. The offence carries a maximum penalty of life in prison.

He was picked up near his home in western Sydney on Sunday, and police said they feared he had plans to attack an Anzac Day service honouring Australian soldiers the following day.

Australia has for months been concerned about home-grown extremism and raised the terror threat alert level to high in September 2014.

The Australian newspaper said the teenager had been part of a deradicalisation programme designed to steer youth away from extremism and thwart any recruitment by the Islamic State in Iraq and Syria (ISIS) group.

As part of the programme he was given a gym membership, taken to English-language sermons at a mosque and visited regularly by community police, it said.

On Monday, Justice Minister Michael Keenan said Australia was not immune to the rise of the so-called ISIS group.

"Unfortunately this is part of a pattern that we have been observing where younger and younger people are targeted and incited to go and commit an act of terror," he said.

The boy is expected to apply for bail on Friday.