Danny Lim assaulted by man at Strathfield train station in Sydney

Footage of the moment beloved Sydney activist Danny Lim was assaulted at a Sydney train station can be revealed for the first time after the father-of-five responsible for the attack was fined.

CCTV released by the Local Court showed Ming Wiseman, 66, angrily confront and punch Mr Lim during a fiery confrontation in front of shocked onlookers, including school children, on the Strathfield Station concourse on September 22 last year.

In court this week, Wiseman pleaded not guilty to assault occasioning actual bodily harm.

However Magistrate Vivien Swain rejected his argument that he was acting in self defence, finding him guilty and recording a conviction.

The court heard that Mr Lim - who is well known around Sydney for wearing his trademark sandwich boards spruiking peace and positivity - suffered a red mark to his left eye after being struck with a right fist during the scuffle.

CCTV played in court showed Wiseman walking through the ticket gate at 3.21pm, carrying a backpack and wheeling his shopping trolley.

The court heard the pair had also had a confrontation at the same train station earlier that day but it became physical when Wiseman came across Mr Lim for a second time.

Mr Lim, who was 79 at the time, can be seen on the video talking to a station employee with one of his sandwich boards over his chest bearing slogans about 'peace' and 'love'.

At the time he was campaigning for the the Yes vote for the Voice to Parliament.

Wiseman placed his shopping trolley and bag down by two bins, angrily pointing his finger at Mr Lim as he approached.

During his evidence to the court Mr Lim said that he heard someone approach from behind uttering profanities.

The footage captured Mr Lim backing up against a wall before a physical altercation ensued.

During this week's hearing, the police prosecution conceded that Mr Lim threw a punch as he attempted to defend himself.

Video showed the pair were involved in a physical altercation before it was broken up by a young woman in a black shirt.

'He swung with his right fist,' Mr Lim said during his evidence, before adding he was struck on the left side of his face.

Magistrate Vivien Swain found that Wiseman struck Mr Lim in the face during the melee, despite Wiseman's claim that Mr Lim had intentionally inflicted his own injuries - an allegation that was strenuously denied by the activist during his evidence.

When he was stopped by police a short time later, Wiseman claimed he acted in self defence saying: 'I didn't punch and he started first.'

The court heard that Wiseman and Mr Lim had previous run-ins at Burwood and Town Hall train stations.

Wiseman was convicted and fined $600 and Magistrate Swain also made an 18-month AVO for Mr Lim's protection.

In court on Monday, Wiseman described Mr Lim as a 'disgrace' and said he had taken offence to some of his signs which included the word 'CVN'T'.

Following the incident, Wiseman uploaded a video to YouTube titled 'I have duty to stop him.'

'He's a liar. He's actually a faker,' Wiseman said during the 22-minute video.

'He's a disgrace of our Chinese community so I have to expose him whenever I can.'