A 28-tonne container handler almost tipped into the harbour after falling through a rotten wharf at PrimePort Timaru, last week.

The forklift was owned by Specialist Container Services, reported The Timaru Herald. It had to be lifted by crane after one of its wheels crashed through planking on the number one wharf.

Manager Chad Hunter said the forklift was being driven along a sealed section when a wheel slipped on to the wooden wharf and went straight through the planking.

"It's just really rotten wood that caused it - we're lucky it didn't go further," he said.