Alan John Scott was killed on Monday while doing roadside clearance work in Le Bons Bay, near Akaroa.

The man killed in a workplace accident on Banks Peninsula was mowing grass on a roadside when he died.

Alan John Scott, of Ohoka in the Waimakariri District, was killed on Monday while working in Le Bons Bay, near Akaroa.

Canterbury Police rural area commander Inspector Peter Cooper said Scott was driving a tractor with an attached mower unit.

The 70-year-old worked for Delta, a Dunedin company that was subcontracted to do roadside vegetation clearance on the peninsula.

The mower became entangled with wire, which Scott attempted to remove by lifting up the boom, or reach arm, connecting the mower to the tractor.

"He's in the process of trying to untangle [the wire] and for some reason he's been struck by the mower unit," Cooper said.

Scott suffered head and chest injuries and died. The tractor was stopped at the time and he did not sustain any cuts from the mower, Cooper said.

"Our thoughts go out to Alan's family, friends and colleagues," Delta chief executive Mike Costelloe said.

"We have been in contact with Alan's family to offer our full support to them at this very sad time."

Scott, who worked in Delta's environmental services team in Christchurch, was described as a well-respected colleague.

WorkSafe was investigating and police were also investigating on behalf of the coroner.

Costelloe said Delta would also carry out its own investigation.