Victoria Police has launched an internal investigation into the actions of two Protective Services Officers (PSO), after viewing extraordinary CCTV footage which shows two teenage boys being repeatedly sprayed with capsicum foam just because one did not have a valid railway ticket.

The 17-year-olds, referred to in this story as Stephen and Paul for legal reasons, were trying to catch a train from Springvale into the inner-city Melbourne.

Stephen did not have a valid ticket so he jumped the ticket turnstiles and was stopped by two PSOs, Matthew Sargent and Michael Rice.

After giving his name, address and date of birth, Stephen decided to make a run for it.

His friend, Paul, followed him and they jumped on a waiting train, with the officers in pursuit.

The CCTV footage shows the PSOs dragging Stephen off the train and forcing him to the ground on the platform.

Paul, concerned for his friend, ran over to the officers and told them to "get the f... off" his friend.

"I was really concerned about my good mate and I could see that he was in distress and the PSOs were handling him pretty rough. That's why I approached them," Paul told 7.30.

Paul had not broken any law, but for some reason, the officers decided to spray him and his friend with capsicum foam. The boys were sprayed three times.

On the first spray, one of the boys was about a metre from the platform edge and a moving train.

Members of the public were almost foamed as well.

The second time, in the mayhem, one of the PSOs was sprayed.

The third time, the boys were facing the wall, trying to protect themselves from foam.

The vision has shocked Victoria's Commissioner for Children and Young People, Bernie Geary.

"Anybody who's watching this who has got 17-year-old, 16-year-old children who are out on the streets for whatever purpose should be really concerned," he told 7.30.

"I would've thought that capsicum spray is life or death.

"And in this video, obviously these children are a threat to nobody.

"In fact, they look to me as though they are acting in a fairly benign way."

PSO admits in court his allegations possibly false

Paul later told the Children's Court the experience of being sprayed was like his entire body being "on fire".

"Just the worst experience you'll ever find," he told 7.30.

"You feel burns all over your eyes, you're pretty much blind - it's the worse experience ever."

Paul was charged with assaulting and hindering the two PSOs, but the officers' version of the incident, in sworn evidence, differed significantly from the CCTV evidence.

The officers said Stephen fell to the ground after a "struggle", but the CCTV showed Stephen fell because of a coordinated trip by both officers.

Mr Sargent said he believed Paul was "posing a threat", "swinging his arms" and "attempting to lash out".

After watching the CCTV footage, Mr Geary rejected that interpretation entirely.

"He's standing there very calmly, isn't he? In fact the only one waving his arms about is the officer," Mr Geary said.

Under cross-examination, Mr Sargent finally admitted his allegations did not stack up.

Barrister James Anderson asked him if he now agreed his perception was "in fact, false".

"Possibly, yes," Mr Sargent replied.

The Magistrate asked Mr Sargent why, on the third spray, he would "deploy capsicum spray if he's got a hood over his face, facing the wall?".

"Because he was trying to lash out," Mr Sargent said.

"So you sprayed him with foam because he was trying to protect himself from foam?" the Magistrate countered.

"Correct," Mr Sargent replied.

Mr Anderson said: "At that stage, it was just a (capsicum) spray party."

Paul's solicitor Matthew Wilson said: "The only risk that was presented here has been a result of the actions of the protective services officers.

"Actions that placed the public in danger, my client, his friend, and ultimately the officers involved."

Ambulance not called for teen struggling to breathe

After the capsicum spraying had ended, the police arrived.

They held Paul's face down, pinning him to the ground with a boot, and cuffed his hands behind his back.

Police gave the boys so-called "after care" - that involved police tipping cleaners' mop buckets of water over their heads for 20-30 minutes to flush out their eyes.

"(The capsicum spray) spread from just my eyes into my whole, entire body because the water mixed with the chemical and it would go all over my body and I would feel the burning sensation everywhere," Paul told 7.30.

He described the pain as a 10, on a scale of one to 10.

While the boys were left handcuffed on the platform, the officer who had been foamed, Michael Rice, was escorted to a sink to flush his eyes.

Mr Sargent had also called an ambulance for his partner, who was having difficulty breathing.

The teenage boy Paul, who has asthma, was also finding it hard to breathe. But no-one thought to call an ambulance for him.

When quizzed about this by Paul's barrister, Mr Sargent replied: "I was concerned for my partner more than (the boy).

"My safety comes first, then my partner's, then the offender's."

'Children are copping capsicum spray in too many circumstances'

Victoria Police's procedural manual on aerosols says capsicum spray must only be deployed where the officer believes there is a reasonable threat of violence or serious physical confrontation.

It should not be used in situations of "passive resistance".

Jane Dixon QC, the immediate past president of Liberty Victoria, said capsicum spray was often used as a method of attack rather than defence.

"Unfortunately, there's been an awareness, a creeping awareness, that children and young people are copping capsicum spray in too many circumstances just to gain their compliance, to stop them running off for example," Ms Dixon told 7.30.

Last month Paul was acquitted of all charges, with the magistrate saying there was no evidence that he intended to assault or hinder the officers.

"I have to say I have real problems with the deployment of foam to (Paul) ... there is nothing in his behaviour or body language which justifies him being sprayed," the magistrate said.

In an earlier case, Stephen admitted fare evasion and completed a diversionary program.

Under Victorian law, the media does not have an automatic right to report Children's Court cases, but in an unusual step, the court's president has allowed 7.30 to tell this story and exclusively broadcast the CCTV because of the serious policy issues it presents.

Lawyers and children's advocates have criticised the heavy-handed behaviour of two PSOs, employed by Victoria Police to protect public safety.

"Please, we would be asking police to acknowledge that this is bad practice," Mr Geary told 7.30.

"And it's extraordinary that they should sit in court and be so in denial of such bad practice.

"Please, hierarchy put your hand up and say 'look, this is bad practice, we'll remedy it'."

A police prosecutor who had represented the force in the Children's Court approval hearing described it as "not (Victoria Police's) finest hour".

7.30 also showed the CCTV to Victoria Police Command.

"When I saw the footage it did raise the question with me 'was the threat there? Was the force proportionate?'" Assistant Commissioner Chris O'Neill, who is in charge of the PSOs and transit police, said.

"That's why I've asked for a review to be undertaken by our subject matter experts, the centre for training, operational tactics and support, who provide the force with their force training in regards to our tactical operational models."

The review will take six weeks.