An accused terrorist has told a court that he was inspired by the Teenage Mutant Ninja Turtles when he concocted a fake plan to use non-existent tunnels to blow up buildings in Melbourne where "leftist" groups met.

Key points: Phillip Galea denied he was a right-wing extremist and told the court he never intended to harm anyone

Phillip Galea denied he was a right-wing extremist and told the court he never intended to harm anyone He said the plot, which was uncovered by police, was "fake" and a "joke"

He said the plot, which was uncovered by police, was "fake" and a "joke" The court heard he had taken photos and collected maps of the targeted sites

Phillip Galea, 35, is on trial for plotting or planning terrorist attacks on Trades Hall in Carlton, the Melbourne Anarchist Club in Northcote and the Resistance Centre in the CBD.

Mr Galea is giving evidence in the Supreme Court of Victoria, telling the jury he is not a terrorist and repeatedly saying that he never intended to harm people or buildings.

He told the court the plan uncovered by police was "fake" and was designed to root out a "dog" informer who Mr Galea believed had infiltrated the right-wing group Reclaim Australia, which he was part of in 2014.

Jurors were told he was inspired by reading about the catacombs and watching the Teenage Mutant Ninja Turtles cartoon when he told the suspected informer about a plan to use underground tunnels in Melbourne to access the targeted locations.

The court heard such tunnels did not exist.

The "fake" plan inspired by the Teenage Mutant Ninja Turtles was meant to root out an informer, Mr Galea said. ( Nickelodeon )

During the trial, the court has heard mercury, cattle prods and other materials were found at his home, as well as a "patriot's cookbook" document, which outlined ways to prepare for an attack.

The court heard he almost blew up his own home while doing a series of "free energy" experiments in 2014 and 2015.

He described himself as a self-made electrical engineer and denied his actions were intended to cause violence.

Instead, he said he had a deep interest in science, in particular the works of 19th-century inventor Nikola Tesla.

He was quizzed by defence lawyer Felicity Gerry.

Ms Gerry: Did you ever intend to use your scientific knowledge to harm people? Mr Galea: No. Ms Gerry: Did you intend to use violence against people? Mr Galea: No. Ms Gerry: Did you intend to attack or destroy any building? Mr Galea: No. Ms Gerry: Did you intend any form of terrorist attack? Mr Galea: No.

He told the court documents taken by police mentioning "massacres" and "buildings and destruction" were satirical.

"I intended it to be taken as a joke. People reading it were to think they were reading comedy," Mr Galea said.

'I felt trapped'

The court heard he had written about weaknesses in the structure of the Trades Hall building, in particular that it was 100 years old.

The court heard he had taken photos and collected maps of the targeted sites.

He said he was doing investigative journalism, seeking to find out where leftist groups who had burned Australian flags were located to "expose" them.

He said his plans to make smoke bombs were simply to disperse members of anti-racism group Antifa, who were disrupting Reclaim Australia rallies during 2014 and 2015.

Those rallies had targeted Muslims in Australia.

Mr Galea told the court the plan uncovered by police was meant to be a "joke". ( Facebook )

The court heard that Mr Galea secretly recorded conversations with police, who he accused of refusing to respond to the "criminal" activity of Antifa and other groups.

He believed his phone was being tapped, that he was being followed by police and that they had installed surveillance devices at his property.

"I felt trapped, scared, concerned and extremely angry," he said.

Mr Galea also spoke at length about Islamic extremism, saying he was angered by coordinated attacks in France in November 2015.

He said he was partly motivated by a fear of the establishment in Australia of Islamic housing estates with Islamic schools and mosques like those he said were in France.

"Allowing this to happen in Melbourne would lead to these kinds of attacks here," he said.

He denied he was a right-wing extremist.

"How's your mental health," Ms Gerry asked him.

"Never been better," he responded.

The trial continues.