Firefighters have been called to rescue the driver of a straddle carrier at the Port of Tauranga after a suspected chemical leak.

Fire and Emergency northern communications shift manager Daniel Nicholson said five crews were called to the scene at Sulphur Point at 1.03pm.

The firefighters are investigating a reported leaking container at the port, he said.

One crew was investigating, and the others were on standby.

Nicholson said the port reported a driver of a mobile machine, understood to be a straddle carrier, was feeling nauseous.

"We are working to get them down from the straddle."

Later a reporter witnessed paramedics tending to a Port worker.

In a statement, the port said emergency services had been called as a precaution following the discovery of a potentially leaking container unloaded from a ship.

"An exclusion zone has been established around the container's location while it is examined.

"There are no injuries reported at this stage, but staff working in the vicinity are being checked by ambulance officers."

A reporter at the scene has seen a New Zealand Customs container inspection unit truck enter the port as well as police cars and fire trucks.