A Christchurch dairy owner picked up a cleaver to try protect his shop from three teenage robbers armed with a knife in April (File video).

When three teenagers walked into his store armed with a knife, a Christchurch dairy owner grabbed the meat cleaver he keeps under the counter and rushed them.

The trio, two young men and a young woman thought to be aged between 15 and 17, entered the GJR Dairy on Waltham Rd, Sydenham, just after 2pm on Sunday.

The dairy owner, who did not want to give his name, said he thought they were the same group that robbed his wife at the store less than two weeks ago, taking cash and scaring her out onto the street.

STACY SQUIRES/STUFF The Christchurch dairy owner, pictured here with a meat cleaver, has kept the weapon close at hand for the past 13 years working in dairies to ward off would-be attackers.

"After it happened to the wife I thought there's no way they're going to do it to me. I'm going to go on the offensive and defend what I've got," the man said.

READ MORE: Morning robbery at Sydenham, Christchurch dairy

"I work 100 hours a week for about $2 an hour, and for some little a....... to come in and take that. . ."

STACY SQUIRES/STUFF The open cash register at Christchurch's GJR Dairy after the store was robbed by three people with a knife on Sunday.

Security footage shows one of the offenders walking into the store and dropping to the ground behind the counter. The dairy owner rushes out and strikes him with the cleaver.

Another of the trio then threatens the man with the knife. The man retreats to a back room before coming out again as the group, dressed in hoodies, start to ransack behind the counter.

"They started threatening me with the knife and waving it around. I thought 'it's either going to be him or me, and it's not going to me', so I thought I'd better get back."

STACY SQUIRES/STUFF The three robbers, with one knife between them, entered the Waltham Rd dairy about 2pm on Sunday.

After again retreating to the back room, the dairy owner said he hit a panic alarm and called police while the young people pillaged the cash register and stole packs of cigarettes from a cabinet.

"It makes me feel like I wanna get out of the shop business now because what the Government is doing with cigarette prices and everything – it's just going to make it worse," the man said.

"A lot of people just can't afford them now, and they're resorting to this."

STACY SQUIRES/STUFF The dairy owner thought the three offenders were aged between 15 and 17. There were two young men and one young woman, he said.

In the past 15 years working in and owning dairies, the man had been robbed five times. This time the offenders made off with about $100 in cash and the cigarettes.

To protect himself, the man said he had kept a meat cleaver close at hand for the past 13 years. He had used it before and had no hesitation doing so again.

Police were called to the store about 2pm. The shop was closed for the remainder of the afternoon as police reviewed the footage and examined the shop, on Waltham Rd near the corner with Hastings St East.

STACY SQUIRES/STUFF The offenders, thought to be teenagers aged between 15 and 17, made off with packs of cigarettes and about $100 in cash from the till.