But a review of his home security system uncovered a shocking secret.

CCTV footage showed an ACT police officer had fired capsicum spray at the chained dog during a search of Mr Storay’s unoccupied Griffith home last month.

The 29-year-old owner, through his lawyers at Canberra law firm Ben Aulich and Associates, lodged an official complaint with the Australian Federal Police. The incident is currently under investigation by AFP's Professional Standards.

RSPCA ACT chief executive Tammy Ven Dange said the behaviour had been “inexcusable” towards a dog that was tethered and obviously could not hurt the officer.

“It doesn’t look like the officer acted appropriately,” she said.

“Normally the AFP is a good partner of ours and helps us with a lot of investigations.

“We’d be more than willing to help the AFP with the investigation into this case.”

Acting chief police officer Commander David Pryce tweeted an assurance that police were taking the matter seriously.

"I've read all comments and criticisms: I know we've let you down Canberra. A professional standards investigation is occuring," the tweet said.

Police searched the home on May 1 in relation to a dangerous driving charge.

Mr Storay – who is known to police – was not at home at the time and no items were seized. Footage of the incident shows Laps – a bull mastiff cross – tethered to a chain in the back yard.

A plain clothes AFP officer can be seen barking at the dog. The dog charges but is stopped well short of the man by its chain. The officer then shoots a burst of oleoresin capsicum spray directly at the stationary animal and it quickly retreats out of sight.

Minutes later, three AFP officers can be seen apparently laughing, with one recording on his mobile phone. The officer who used the spray later throws a stick towards the animal and leaves.

The dog allegedly suffered red, watery eyes and was distressed but did not require veterinary treatment.

Mr Storay said two-year-old Laps’ injuries had been overwhelming psychological.

He said the normally friendly dog – who Mr Storay trusted to play with his children, aged eight and three –had “cowered”, been “stand offish”, and seemed "really shocked" after the incident.

“I was pretty disgusted and didn’t know what to think,” Mr Storay said. “Laps was on a chain and there was a 480 kilogram break point on his collar.

“There was no need for that. He wasn’t going anywhere."

The incident had also been a financial burden for the family.

Mr Storay had since constructed a $1200 pen for the dog and now only walked him at night to avoid people and other animals.

“Hopefully he’ll go back to normal, there’s plenty of love for him here,” he said.

Mr Storay’s lawyer, Peter Woodhouse, said AFP Professional Standards originally classified the complaint as a level 1 public relations issue – usually reserved for inappropriate behaviour in relation to minor management or customer service complaints.

But the matter has since been upgraded to a level 3 matter at the law firm’s insistence after viewing the footage.

He said his client had been concerned the AFP would not take the matter seriously.

"It is cowardly for anybody to treat an animal in this way. [But] the fact that it is a police officer supposedly executing his duty is appalling," Mr Woodhouse said.

He said the officer who sprayed the dog had acted in a highly inappropriate manner.

An AFP spokesman said the allegations had been taken seriously.

"This matter is currently subject to an investigation by the AFP's Professional Standards area," the spokesman said.

"AFP professional Standards have reviewed the footage and the matter is currently subject to an ongoing internal investigation. While this remains ongoing, it would not be appropriate for the AFP to comment any further."

It later put out a further statement.

"ACT Policing does not condone cruelty to animals in any form. All officers are required to report all use-of-force actions, and the reported use of oleoresin capsicum spray is part of this requirement," it said.