UPDATED 11.14AM: An Air New Zealand plane has had to turn back on the way to Samoa this morning, sparking an emergency at Auckland Airport.

NZ296 from Auckland to Apia returned to Auckland Airport after pilots detected an engineering issue shortly after take-off.

A small amount of hydraulic fluid caused by the engineering issue dripped onto the hot brakes after the aircraft landed, causing smoke.

Air New Zealand says the aircraft landed safely around 9.50am.

There were 293 passengers onboard.

Engineers will now inspect the aircraft.

The airline says some witnesses on the ground have wrongly interpreted it to be a fire.​