The death has prompted renewed calls for a high level of safety awareness regarding farm vehicles, including no-one under 16 being allowed to ride adult-sized bikes.
Emergency services were called to a farm on the Lorneville-Wallacetown Highway at 5.30pm, after reports the boy - named by police as Charlie John Vercoe - was seriously injured.
He later died at Southland Hospital as a result of his injuries.
The boy was out riding a quad bike - an adult-sized Honda 420cc - with his 12-year-old brother at a farm they were visiting when the crash occurred, Detective Sergeant Grant Johnstone, of Invercargill, said.
Police were investigating the crash, initial indications showing Charlie lost control of the quad bike he was driving, which rolled before landing in a ditch of water. Police confirmed the Invercargill boy was wearing a helmet at the time of the crash.
Det Sgt Johnstone said the incident was a tragic reminder of the need for a high level of safety when using farm vehicles. The investigation was at an early stage and would be completed on behalf of the coroner.
The owner of the property where the incident took place declined to comment when contacted by the Otago Daily Times yesterday.
The mother of the dead child posted a picture of Charlie with a miniature horse on her Facebook page on Monday night.
The family have requested privacy.
Federated Farmers health and safety spokeswoman Jeanette Maxwell told the Otago Daily Times the organisation recommended no-one under 16 be allowed to use an adult-sized quad bike.
''Adult bikes are huge. A little person won't be capable of riding one, as they just aren't tall enough.''
Children who did ride on bikes, such as miniature bikes or on an older person's lap, should always wear helmets, she said.
The federation, which is a member of the Agricultural Health and Safety Council, had been working to improve New Zealand's on-farm safety record, she said. This safety record appeared to have improved over the Christmas-New Year holiday period, she said.
There are an estimated 100,000 quad bikes on New Zealand farms.
The federation recommended using safety aids to alert riders if their bike was in gear, training and using age-appropriate bikes and helmets, which was having a positive safety benefit, she said.
Late last year coroner Brandt Shortland, after several quad bike deaths, made several recommendations, including that children be prevented from riding adult quad bikes.
He also said users should wear a helmet, and the appropriate vehicle should be chosen for each job.
