Victoria Police is being urged to offer more training to help officers recognise the symptoms of seizures after a man with epilepsy was critically injured during an arrest in a town south-east of Melbourne.

Key points: Witnesses said the man's head was split open when he was arrested in Wonthaggi on Monday

Witnesses said the man's head was split open when he was arrested in Wonthaggi on Monday Epilepsy Action Australia CEO Carol Ireland said sometimes people can become aggressive coming out of a seizure

Epilepsy Action Australia CEO Carol Ireland said sometimes people can become aggressive coming out of a seizure Ms Ireland said police need more training to recognise an epileptic seizure

The 33-year-old had his head split open and was flown to Melbourne's St Vincent's Hospital after being arrested in Wonthaggi on Monday.

Footage of the arrest showed police officers on top of the man and his face covered in blood.

WARNING: This story contains a graphic image some people may find distressing.

Witnesses said he had suffered an epileptic seizure in the main street of Wonthaggi and became aggressive, punching at car windows and later at police, before being subdued with capsicum spray.

Sorry, this video has expired Man arrested in Wonthaggi

The man's friend, Damien Hall, has accused officers of using unnecessary force during the arrest.

"They put handcuffs on him, he's there frothing at the mouth, he can't breathe, there's blood coming out of his mouth, blood pissing out of his head everywhere, the police sort of ganged him," he said.

A spokesman for Victoria Police confirmed the man was injured while being detained.

The Police Professional Standards Command is overseeing an investigation into the arrest, including the level of restraint used.

Epilepsy Action Australia chief executive officer Carol Ireland said while it was not common for epilepsy sufferers to become aggressive, it does happen.

"Epilepsy is a complex condition and everyone experiences seizures differently," Ms Ireland said.

"What we call the postictal stage — when they're coming out of a seizure — they're very disorientated, they've just had a disruption to their electro-chemical activity in the brain, they're confused, they're disorientated, some people will become aggressive."

The man's head was split open during the arrest and he was treated in hospital in Melboune. ( Supplied: Damien Hall )

Ms Ireland said it was important for sufferers and their families to have a seizure management plan, so that they understood the course a seizure might take and how the person may wake up.

'Restraining is the worst thing you can do'

Bass Coast Shire councillor and local real estate agent Brett Tessari works nearby and saw the man having the seizure.

"His mother didn't want me to call the ambulance because she said her son has epileptic fits often and when he comes to he becomes aggressive, and that's exactly what happened," Cr Tessari said.

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Mr Tessari said one of the police officers grabbed the man and threw him to the ground.

"That's a really unfortunate incident, really unfortunate," Ms Ireland said.

"The problem is the police probably didn't recognise it was a seizure. If they had, the first thing we say is you don't restrain the person.

"The person isn't conscious, they don't know what's actually occurring and it is an electro-chemical imbalance, so we would say 'don't restrain the person, ensure that they're safe, put something under their head, let them go through the seizure which will usually only take two to three minutes and just reassure them when they wake'.

"Obviously the police haven't recognised here that it's a seizure and they've restrained the person which is the worst thing you can do."

'Police are not doctors,' union says

The Police Association defended the officers' actions, saying their first priority was to protect the community and themselves.

"Our members aren't clinicians, they're not doctors and they're not psychiatrists," secretary Wayne Gatt said.

"They can't possibly have training and expertise across the enormous range of conditions that people in the community confront. That's just simply an expectation that is too hard to meet."

Epilepsy Action Australia has contacted Victoria Police to offer training for officers.

"If police were able to recognise the seizures more easily I think it's a better outcome for everyone," Ms Ireland said.

"If his mother and friend were saying 'this is an epileptic seizure' then that should have been the warning bell."

Mr Gatt said police had a really good working knowledge of first aid and how to deal with people experiencing mental health crises.

"Police have a job to do and I think it is unrealistic to expect them to provide a clinical diagnosis of somebody in a short period of time, sometimes seconds, in dangerous circumstances," he said.

"Police don't go to these situations wanting to use force.

"It's unfortunate when people end up being injured as a result of police contact but sometimes it's an inevitable outcome when police are dealing with violent situations."