New mothers and babies at North Shore Hospital had to endure the stench of human waste after a sewage leak in the maternity ward

A Health NZ Waitemata staff member says she'd heard reports from her colleagues about sewage leaking from toilets and showers.

She says while about 10 beds were closed, some parts of the ward remained open to postnatal patients.

Health New Zealand says a pipe blockage called a small leak into an isolated area - but there was no impact on patient care and the area's now fully operational.

It says the situation was closely managed by its infection prevention control team to prevent any illness - and provisions were in place if required.