A spokesperson said a total of 5228 containers were moved by road and 151 by rail on Monday. About 30,000 containers had piled up on the docks while operations were suspended.

DP World Australia has operations in Brisbane, Melbourne, Sydney and Fremantle and handles about 40% of the cargo that arrives in, or leaves, Australia.

The company was still able to allow ships to offload or pick up containers, but the IT systems that trucks use to communicate with the stevedore were not operating from Friday until Monday for safety reasons.

A statement issued by DP World Australia on Monday said: "The ongoing investigation and response to protect networks and systems may cause some necessary, temporary disruptions to their services in coming days.

"This is part of an investigation process and resuming normal logistical operations at this scale."

It said the resumption of operations did not mean that investigation of the incident was over, and that ongoing remediation would continue for a while.

No attack group has claimed responsibility for the hit on DP World Australia as yet.

DP World is owned by the emirate of Dubai which is part of the United Arab Emirates.