Authorities have uncovered a series of maintenance issues on Australia Post trucks.

Members of NSW Police and the Roads and Maritime Services (RMS) say they will likely conduct a deeper investigation following the surprise vehicle inspections at an Australia Post parcel lodgement centre at Chullora.

In fact, the authorities have foreshadowed a long enforcement campaign against the parcel delivery sector.

It comes after inspectors arrived at an AusPost parcel lodgement centre to carry out mechanical compliance inspections and download data from engine control modules.

They were there to collect data following weeks of intelligence-gathering, which revealed a number of speeding offences.

But upon closer inspection of the194 trucks and trailers, the crew issued 22 major defect and 10 minor defect warnings. The defects involved brakes, tyres, suspension and oil/fuel leaks.

It is the latest move under the banner of Operation Despatch.

Twenty-three vehicle engine control modules were downloaded, and all were found to be non compliant.

Four units had records of speeds over 100km/h.

“These operations will continue until the dangerous and potentially deadly behaviour ends – even if we have to visit each facility one by one,” NSW Police assistant commissioner John Hartley said.

“Given other tragic events involving heavy vehicles resulting in serious injury and fatal crashes in recent times, these operations are focused on prevention through enforcing safety for the benefit of all road users.”

Hartley says Operation Despatch is important for ensuring heavy vehicle safety and compliance across all sectors of the industry.