A man who filmed himself coughing and sneezing on Christchurch supermarket shoppers during the coronavirus lockdown has today been jailed for 16 months.

Raymond Gary Coombs, a 38-year-old roofer, was arrested after uploading a video on Facebook which showed him pretending to cough on shoppers at Fresh Choice supermarket in Barrington on April 6 – during the nationwide alert level 4 coronavirus lockdown.

He later took down the video and apologised, claiming he'd had too much to drink.

"It was a foolish, insensitive act, and I regret it – I really do," he later said in Christchurch District Court, pleading guilty to one charge of offensive behaviour.

Fresh Choice Barrington reported the video to police.

Coombs' stunt was branded "dangerous, selfish and stupid" by a judge today, adding he had attracted "significant notoriety in part to your own stupidity".

He was also sentenced on unrelated, admitted charges of driving with excess breath alcohol where he recorded an "astronomical level", careless driving, refusing a blood specimen and breach of release conditions.

The court heard that Coombs filmed himself smiling and laughing as his coughed and sneezed at fellow shoppers who were often only half a metre away.

"This was at a time when everyone was highly concerned about their own safety," Judge Raoul Neave said.

Given the climate at the time, the context his offending came in and coupled with his history, the judge said it was hard to think of any more offensive behaviour.

It was the kind of nuisance behaviour that has "plagued" his life, Judge Neave said.

Defence counsel Kathy Basire said Coombs suffered "quite significant childhood trauma" and knows he needs to abstain from alcohol.

The court heard that he fell off the wagon after his mother's death – and was under the influence of alcohol during his supermarket stunt, which has apologised for several times.

He wants to get a place at an approved residential rehabilitation facility in the community so he can stay alcohol free, his lawyer said.

Judge Neave sentenced Coombs, who has been in custody since April 13, to 16 months' imprisonment, with the ability to apply for home detention once a bed at a residential rehabilitation centre becomes available.

On the offensive behaviour charge alone, a fine-only matter that relates to the supermarket coughing incident, Coombs was fined $750 plus ordered to pay court costs of $130.

The judge said only time will tell if he's genuine in his desire to turn his life around.

Coombs' lawyer at his first court appearance said he'd been watching prank videos on YouTube before he recorded the footage in the supermarket.

Judge Jane McMeeken said he owed the country an apology, describing the incident as serious.

She noted that it was not an isolated incident - Coombs had earlier uploaded another video in which he pretended to have the virus. He later tested negative for Covid-19.

"This is an unprecedented time in New Zealand's history ... many people are suffering," McMeeken said.

"Your behaviour would've added to that suffering.

"It's vitally important to our country we get out of lockdown as soon as possible. Your actions could've stopped that."

Prime Minister Jacinda Ardern described Coombs as an "idiot".

He was initially facing charges of criminal nuisance and failing to follow a Medical Officer of Health's orders.

The criminal nuisance charge was amended to one of offensive behaviour and the other was dropped.

It's not Coombs' first brush with the law over a stupid "prank".

In 2008, Coombs terrorised Christchurch after making bombs with dry ice and soft drink bottles and leaving them at various spots across the city - at Northlands Mall, a service station, a rubbish bin in the city, a planter box at the Palms Mall, and at the bus exchange.

When a cleaner found one of the bottle bombs at Christchurch bus exchange, and started to unscrew its lid, it exploded. The power of the explosion, which was likened to a military thunderflash device, left the cleaner with a permanent disability, suffering from ringing in his ears and headaches from bright lights, a court earlier heard.

An explosion at Northlands Mall caused people to fear part of the building had collapsed.

Coombs admitted what his lawyer called "a prank gone wrong" and was jailed for two years and three months.