Havelock North businesses have more time to apply for financial help following a devastating gastro outbreak.

The Hastings District Council's business relief package is available for those affected by the water contamination crisis, where struck down more than 5000 people with campylobacter.

The business package is worth $100,000.

Council chief executive Ross McLeod said the deadline was originally today - but it's been extended for a week.

He said so far, 24 applications have been received and they're confident there's enough money to go round.

"I think it will be around about enough. We've got a little bit extra we can draw on if we need to, but I think the amount that was put aside is going to be in the right ball park."

Mr McLeod said some applications have been turned down, but wouldn't comment on exactly how many.

"If there's not demonstrable need for assistance or if the water contamination event hasn't had a demonstrable impact, those are probably some of the reasons why we might not grant assistance."

Havelock North Business Association spokesman Aimee Stewart said there hasn't been a lot of transparency from the council about the number of approved and declined applications.

She said some businesses want to know why they've been turned away, and what other help is available.

Meanwhile, a second case of Guillain-Barré Syndrome has been linked to the gastro outbreak.