Housing New Zealand is apologising for giving the Mongrel Mob the contact details of a woman who complained about them.
The woman and her two children were forced to flee a state house in Pomare, Lower Hutt, last month, blaming intimidation and bullying by the gang.
Housing New Zealand says it served five mob members with eviction notices - which included the complainant's contact details and that of a employee.
Housing New Zealand chief executive Lesley McTurk measures have been taken to ensure both are kept safe and she is "exceptionally sorry" for the mistake.
An internal investigation is under way.
The Mongrel Mob says it has no intention of harming the tenant who complained.
A spokesperson, known as Fats, says gang members are under "strict instructions" not to make contact with the woman.
He also says they have got nothing against the Housing New Zealand employee.