The ‘nanny state’ debate has reignited after a man filming police and a sniffer dog ‘wasting’ resources was then 'hassled' by an officer.

A man was changing trains at Sydney's Central Railway Station when he came across 10 police officers with a sniffer dog and began filming what he believed to be the use of excessive resources.

Video then shows a Senior Constable approach the man and ask to see his ticket, before questioning the man's movements, suggesting he was 'suspicious' in light of the 'current terrorism climate', and even asking whether he had a mental health issue.

According to the man filming, the exchange was evidence of ‘a real police state’.

NSW Police confirmed to Daily Mail Australia it was a 'drug detection operation'.

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A man was changing trains at Sydney's Central Railway Station when he came across 10 police officers with a sniffer dog and began filming what he believed to be excessive resources used to 'sniff out drugs'

Video of the exchange about two weeks ago has been viewed more than 420,000 times since it was posted to the Save New South Wales Facebook page on Sunday.

The man said he’d arrived at the train station from Gosford and was carrying luggage to head to Circular Quay for a cruise.

He decided to film the police and dog, before an officer photographed him and another came over to check his ticket and ‘generally throw his weight around’, according to the man filming.

‘Is there any reason why you’re filming us, sir?’ the Senior Constable said.

‘Given the current terrorism climate and stuff sir, I’m just saying.’

The officer then asked for the man’s name, where and why he was travelling.

Video then shows a Senior Constable approach the man and ask to see his ticket, before questioning the man's movements, suggesting he was 'suspicious' in light of the 'current terrorism climate', and even asking whether he had a mental health issue

According to the man filming, the exchange was evidence of ‘a real police state’

‘Is there any reason why you’re filming us, sir?’ the Senior Constable said. ‘Given the current terrorism climate and stuff sir, I’m just saying.’ The Snr Const then abruptly walked off (pictured) after asking the man whether he had any mental health concerns

‘I respectfully decline to answer that question,’ the man said – pointing out he was not reasonably suspected to have committed a crime, witnessed a crime, nor had he been given an order to move on.

The Snr Const then asked whether the man had ‘any mental health concerns’, before abruptly walking away with another uniformed officer.

‘Welcome to the fascist police state that we have in NSW. Well done Mike Baird,' the man wrote alongside the video.

In his Facebook post, the man said he’d been made to feel as though he was doing something wrong.

‘I don’t for one minute believe this has anything to do with terrorism. The dog’s there to sniff out drugs, and if I had any, do they really think I’d stop and film the operation, thus opening myself up to this humiliation and scrutiny?’

However, not all viewers agreed with him.

‘So despite the recent terrorists acts across the world your [sic] complaining about police showing a presence in a major train station,’ one person wrote in the comment section.

According to figures provided by NSW Police last year, ‘drug dogs falsely indicate the presence of drugs 64-72 per cent of the time’

‘I don’t for one minute believe this has anything to do with terrorism. The dog’s there to sniff out drugs, and if I had any, do they really think I’d stop and film the operation, thus opening myself up to this humiliation and scrutiny?’ the man wrote alongside the Facebook video

‘Of course they are going to ask a guy with baggage standing in the middle of the station filming them for no reason a few general questions.’

Another mentioned it was not illegal to film in public, and said the Snr Const appeared to view the man ‘as being guilty until proven innocent’.

Another commented the man was ‘being treated with suspicion for exercising his rights, also known as our rights’.

A further commenter wrote she accepted ‘police need to be policed’ but couldn’t ‘see any value in this particular video’.

She agreed the man filming had done nothing wrong, but that the video showed nothing more than that the Snr Const ‘needs more training’.

NSW Greens MP David Shoebridge told Daily Mail Australia it was 'grossly inappropriate' for police to question a person's mental health 'simply because they are filming with a mobile phone in public'.

'It is perfectly lawful and reasonable to film police in a public place, especially in circumstances that demonstrate the waste of police resources in drug dog operations.

One commenter said she accepted ‘police need to be policed’ but that she couldn’t ‘see any value in this particular video’

Video of the exchange about two weeks ago has been viewed more than 420,000 times since it was posted to the Save New South Wales Facebook page on Sunday

'Most people would want these police officers out there tracking down serious crime and apprehending violent offenders, not all standing around the one dog,' Mr Shoebridge said.

'To have 10 police officers and a drug detection dog on duty all to identify small scale drug possession offences is by no means an effective use of resources.'

He called the incident 'aggressive policing'.

In a statement from June 2015, Mr Shoebridge said the dogs were an ‘ineffective and resource-intensive police power’.

‘The inaccuracy of the drug dog program, the violations of civil liberties, and the inappropriate targeting of vulnerable people mean it should be stopped,’ the statement said.

According to figures provided by NSW Police last year, ‘drug dogs falsely indicate the presence of drugs 64-72 per cent of the time’, according to the Greens MP.

NSW Police told Daily Mail Australia the officer's questions 'were appropriate and all above board'.

'The officer's comments regarding terrorism were based on the current heightened alert level,' police said.

NSW Police replaced RailCorp transit officers to provide security on public transport in May 2012.

Daily Mail Australia has contacted Premier Mike Baird for comment.