Farmers may have to contribute to a new fund based which would cover the cost of biosecurity threats.

Speaking after the release of the Budget on Thursday, Finance Minister Grant Robertson said that New Zealand needed to start taking a different approach to biosecurity incursions.

That came after the coalition Government committed $85 million to the frontline response to Mycobacterium bovis, a bacterial disease which has infected tens of thousands of cattle across New Zealand and is threatening one of the country's key export industries.

Speaking to TVNZ's Q+A today, Robertson said there were an increasing number of biosecurity threats to New Zealand.

"We have to be realistic," he said. "We can't just sit there and wait for these things to happen.

"We know they're happening more regularly, and I want us to get ahead of that."

Incursions like M bovis forced the Government and industry to "scramble around" for the money to respond to them, he said.

Organisations like the Accident Compensation Corporation (ACC) and the Earthquake Commission were designed to get ahead of shocks or disasters, and the Government was working on something similar for biosecurity.

Robertson has asked the Treasury and the Ministry for Primary Industries to investigate what a biosecurity fund could look like, how much the Government would contribute, and how much industry would contribute in future.

That could mean new costs for farmers who have already had subsidies for irrigation scrapped and could face new charges for climate pollution and freshwater use under the Labour-led Government.

Robertson said farmers already paid for the response to biosecurity incursions. A fund would allow industry and the Government to be more reactive, rather than paying millions in eradication and containment costs.

So far, the Government has paid $4.5m in compensation to farmers affected by M bovis. A total of 117 claims have been made for compensation.

The ministry is still working on eradicating the disease, but accepts that it is likely to shift its approach to containment because of its rapid spread.