A number of Work and Income staff have been assaulted since last year's fatal shooting in Ashburton.
In the year to the end of June 2015, 11 Work and Income staff were seriously assaulted, and 413 beneficiaries trespassed for threatening behaviour, figures released under the Official Information Act reveal.
In the 2013/14 financial year, 22 WINZ staff were assaulted and 163 beneficiaries trespassed.
Last September, Ashburton Work and Income staff members Peg Noble and Leigh Cleveland were killed and another was injured when they were shot at their workplace.
A 49-year-old man, Russell John Tully, is facing charges.
Since the Ashburton attack, an extra 250 security staff have been employed at Work and Income offices, and a tougher line taken towards abusive and violent behaviour.
Associate Social Development Minister Jo Goodhew said copycat incidents had occurred.
"We've seen a number of people threatening staff based on what they've read in the paper."
"They think that that's going to get extra attention, but when they get that extra attention I'm not sure it's the extra attention they thought they wanted."
Mrs Goodhew said those incidents were treated very seriously.
At present more than 550 people are trespassed from WINZ offices, with notices in place for two years.
Ms Brereton said those beneficiaries had to find someone to act on their behalf, or communicate with Work and Income over the phone or by email.
"Lots of people I meet who are trespassed have literacy issues, and they might try and get a neighbour or friend to go into Work and Income."
But Mrs Goodhew was confident that those who have been trespassed were still getting the help they needed.
"That doesn't mean that Work and Income refuses to work with them. We just do it in a way that is much more safe for our staff."
That person would still get what they were entitled to in the way of assistance and support through Work and Income.
Every single assault and trespass incident was reviewed to check if there was any way it could have been prevented, and staff underwent regular training, she said.
CORRECTION: This article originally stated that there had been a surge in assaults on WINZ staff and that 46 staff members had been attacked in a year. This was based on information released by WINZ. WINZ has since apologised to Radio NZ for supplying incorrect information.
The incorrect figures have been removed from the article, as have reactions to news of those figures.