Police have focused on a group of teenagers from Christchurch in connection with the incident on Birchs Rd.
The victim, aged in his 70s, heard a noise on his property about 9.20pm and went outside to find his shed being broken into.
He found a youth aged about 16 to 18 holding a petrol can.
Three other youths ran from the shed and the elderly man was punched in the eye.
Youth crime unit Constable Patrick Sullivan in Christchurch said police had followed up on a tip after the screening of Police Ten 7.
“We have spoken with and will be speaking to more people of interest,” Sullivan said.