Magistrate Geraldine Beattie made the comment in Goulburn Local Court on Wednesday. Forty-year-old Goulburn man, Robert David Hill pleaded guilty to one charge of possessing an unauthorised firearm and one charge of not keeping a prohibited firearm safely.

The court heard that police had visited Hill's home on May 14 in relation to another matter and while there had observed the gel blaster hanging on the main bedroom's wall.

ALSO READ: Man accused of importing drugs awaits another day in court

His solicitor said Hill had purchased the gel blaster from a website one year ago but he was not aware it was an illegal firearm.

The defendant had never taken the firearm outside of his home, nor had he been in possession of it around his children or used it for criminal activity.

"When police were there he made no attempt to hide it and (the defendant) has no firearm matters on his record," the solicitor said.

He urged Ms Beattie to deal with the matter by way of a fine.

ALSO READ: Australia's oldest motorcycle club opens home track in Goulburn

In response, the police prosecutor said the onus was on the person to check the legality of items before purchasing them.

Magistrate Beattie said Hill was entitled to a 25 per cent reduction on his sentence, given his guilty plea.

She said possession of illegal firearms was a very serious offence.

ALSO READ: Street art, lighting and a 'GOUber': How Goulburn could become more "vibrant"

"You cannot have gel blasters in this state...They can enable illegal activity to take place and there are strong reasons for banning them," she said.

Magistrate Beattie said it was important to deter usage and imposed a good behaviour bond and fined Hill $600.

Did you know the Goulburn Post is now offering breaking news alerts and a daily email newsletter? Keep up-to-date with all the local news: sign up below.