The mother of a 5-year-old boy who rode a rollercoaster shut down over safety concerns said she heard a brace or screw come lose and hit the ground.

Sophie Dalziel said she videoed her son, Carter, with his sister-in-law, 14, on the rollercoaster at the Canterbury A&P Show on Friday.

“Towards the end of the video, I heard like a brace, a screw or something come loose and I heard it butt on the ground.

“The guy running it stopped the coaster when they got back to the start, went and fixed it by hand, then carried on with it.

“A person next to me said: ‘Do you not want a wrench or anything? Are you just going to do that by hand?’ and we were like: ‘Okay, that’s a little bit weird’.

“The guy running it didn’t look fazed. It has probably happened before and he has said [to himself] ‘I’ll go fix this and keep on going’,” said Dalziel.

Loose bolts are shown at the Cartoon Coaster at The Christchurch Show, an annual A&P event in Canterbury.

WorkSafe shut down the Cartoon Coaster after sending safety inspectors to the site on Friday.

“A ride at the Canterbury Show has been taken out of action, after WorkSafe was alerted to loose parts that could endanger riders,” WorkSafe told the Herald.

“Following an on-site assessment today, a prohibition notice has been issued which prevents the Cartoon Coaster from being used until WorkSafe is satisfied that safety improvements have been made.”

Dalziel said Carter wasn’t the sort of kid who would normally go on a ride but was quite excited about it.

She said he was quite happy with the ride and “none the wiser as I did not want to freak him out by telling him anything”.

Dalziel said there needs to be regulations or safety checks done and, if there already are, they should be tighter.

The Cartoon Coaster was shut down by WorkSafe.

“Anything that can get packed up on to a little truck like that is worrying to me, but to see it happen, I don’t know if I would want him to go on another ride,” she said.

Other people who attended the show claimed they also saw the fairground ride malfunctioning.

“Bolts were falling out of the rides,” one man claimed on social media.

“These bolts hold the arms for the rollercoaster track. One fell off completely during the time I watched and there were multiple loose bolts on other support arms.”

Images shared to a local Facebook page showed one bolt that had nearly worked free, and a bolt lying on the ground.

Another parent said: “I wouldn’t let me kids on half the rides, even if they were free.”

The Christchurch Show confirmed WorkSafe had been on-site.

“In the interests of public safety, the ride will be closed until WorkSafe is happy for it to reopen,” it said in a statement. “Our No 1 priority is safety first.”