Leaky building syndrome has hit 73 schools nationally, and the problem is far more widespread than previously declared.

Last November, the Ministry of Education said 36 schools had leaking buildings.

But Auckland City Council regulatory claims manager Sally Grey said in a weathertightness report this week that the number was double that.

The ministry has tried to get money from Auckland City to fix some buildings. But the council fought back and won.

"The Ministry of Education brought High Court proceedings against the council and other building parties in relation to three schools with leaky buildings," Ms Grey wrote in her report.

"We understand these three claims may have been somewhat of a test case for the ministry, the outcome of which would then determine the direction for resolving the other 70 known schools with leaky buildings - plus those schools yet to discover leaky buildings."

Auckland City was struck out of all three claims because the council argued successfully that it owed no duty of care to the ministry or to the boards of trustees of schools over non-residential buildings, she said.

It was up to the original owners or developers to retain experts to draw up plans that complied and to supervise construction.

"If the Crown as school owner chose not to retain the appropriate experts, that was a commercial choice and the consequences and costs of that choice should not be imposed on the council and local ratepayers," Ms Grey wrote.

She also revealed a claim against the council over leaks at the Mt Albert Aquatic Centre had been withdrawn.

Mt Albert Grammar School Community Swimming Pool Trust chairman Paul Harrop said repairs would cost more than $1 million.

Problems in construction combined with the air-extraction system's inadequacies were resulting in damage to the building, he said.

Walls and the roof needed repairing.

Mt Albert Grammar School headmaster Dale Burden said leaks in the 24-classroom "E" block will be fixed next year.

Ministry spokeswoman Jodi Ihaka said no statement would be made about leaky schools "due to ongoing legal issues".

She refused to discuss the number of schools or name the court cases which prevented her speaking.

Auckland schools identified by the Ministry of Education last November as having buildings with leaks were:

Auckland Girls Grammar, Otahuhu Intermediate, Botany Downs Secondary College, Edendale Primary School, Glen Innes Primary School, Mt Albert Grammar, Macleans College, Murrays Bay Intermediate, Murrays Bay School, Northcote College, One Tree Hill College, Oteha Valley Primary School, Pakuranga College, Papatoetoe East School, Pinehill School, Pomaria School, Randwick Park, Rowandale School, Summerland Primary, Swanson School, Shelly Park School, Te Kura Kaupapa Maori O Nga Maungarongo.