Updated 1:41pm: The decision on whether Hamilton City Council will recommence water fluoridation ahead of the judicial review will be made shortly.

At a hearing at the High Court in Hamilton this morning, anti-fluoride group, Safe Water New Zealand, stated that recommencing water fluoridation now would prejudice the judicial review which will be held later this year.

In June last year a tribunal voted to remove the chemical from the city's water supply but that decision was reversed in March this year.

Anti-fluoride group: Hamilton has unfair advantage

An anti fluoride group believes Hamilton City Council will have an unfair advantage, if fluoride is returned to the city's water supply ahead of a judicial review.

Safe Water New Zealand wants the council stopped until the review in August.

A hearing on that is underway at the High Court in Hamilton with fluoride returning to the water in around seven days.

The lawyer for Safe Water New Zealand, Lisa Hansen, says if that goes ahead the council will already have the operational equipment to keep the water fluoridated at the time of the judicial review in August, giving it an unfair advantage.