It was passed only two years after the fall of Hitler and just before Pakistan became a country. Now the little-known law could be used to fight dodgy landlords who put tenants in damp homes.

The law, passed in 1947, requires homes to be "free of damp", but it has been largely forgotten. Tenancy tribunals have often sided with landlords, even when dampness was causing serious health problems to tenants.

Now, in a study published in New Zealand Universities Law Review, academics from Victoria and Otago university argue that it is time to resurrect the "free of damp" law to help families who are failing to win redress from tribunals.

In one recent case examined in the study, a tribunal declined to award a family compensation after they were forced to move out when their bathroom ceiling collapsed. The tribunal found there was "no suggestion of structural unsoundness".

In another case in Wellington, members of a family had to spend time in hospital within two months of moving into a leaky damp house, suffering a liver infection, breathing difficulties and urinary infections. A tribunal declined to grant the tenants compensation.

"This was despite the extremely poor state of the premises – there was serious mould and damp problems due to leaks, which rendered the rooms, furnishings and clothing mouldy, smelly and damp," the authors said.

Co-author Mark Bennett, from Victoria University's law school, said the cases showed current tenancy regulations, which specified only that landlords had to keep homes is a "reasonable state of repair", were not enough. There was no explicit requirement for rented housing to have adequate insulation or efficient heating

"It's 'Is the house falling down, are there holes in the wall' sort of stuff," he said.

Co-author Professor Philippa Howden-Chapman, of Otago University in Wellington, is part of group developing rental warrants of fitness. She said expecting tenants to rely on a 67-year-old law that was largely ignored showed just how confused and inadequate rental housing standards had become.

"In 1947, we thought rental accommodation should be dry. What has changed?"

The Government had spent million insulating state homes, which house some of the nation's poorest people, and subsidising insulation in the private housing market. However, it had not committed to minimum standards for rental homes, with Prime Minister John Key last December expressing concern that standards would put pressure on rents.

A warrant of fitness trial of state housing was conducted last year but its results have not yet been made public.

A spokeswoman for Housing Minister Nick Smith said the Government remained "open-minded" about rental warrants of fitness, but any standards needed to be balanced against the cost, which were likely to be passed on to tenants in higher rents.

"We also do not want to remove houses from the market unnecessarily in the middle of a housing shortage."

In 2013, a Statistics New Zealand report found more than a third of Kiwis live in homes they consider cold, damp, or overcrowded. These factors have been blamed for New Zealand's high rates of asthma, skin infections and winter deaths.

Last May, Wellington-based Otago University researchers released a report on a rental housing warrant of fitness scheme, which was piloted in 144 houses in Auckland, Tauranga, Wellington, Christchurch and Dunedin.

Only eight houses passed the warrant's minimum standards nationwide.