The ''disappointing'' attack on a salmon farm net in Twizel means the loss of thousands of dollars, the farm's owner says.
Between Friday night and Saturday morning support ropes around a net at High Country Salmon were cut and about 6000 small salmon were released into the Ohau Canal and Lake Ruataniwha.
High Country Salmon owner operator Peter Logan said it was the first time the business had been attacked in that way in its 17 years of existence.
He said he had no idea who would want to harm the family-run business in such a way.
''We're pretty disappointed that anyone would do that. We don't have anyone particular in mind that would want to do this.''
As a result of the weekend vandalism security cameras and lights have been installed.
He urged the public to come forward with any information which could help the police in their investigation.
''We'll offer a few free fish.''
