Maritime NZ Southern compliance manager Michael Vredenburg said concerns were raised when an uncertified vessel was used in an attempt to tow a barge carrying a digger to Aramoana wharf on Thursday.
The Port Otago work boat Kapu towed the barge and digger to Port Chalmers.
Maritime NZ imposed conditions on the uncertified vessel to stop it from any further towing, Mr Vredenburg said.
"If the vessel again engages in towing, it could be subject to fines or further action."
The Dunedin City Council had arranged for the digger to demolish the old Aramoana wharf.
On Thursday, council parks and recreation acting group manager Tom Dyer said high winds prevented the barge from being offloaded beside the wharf. Mr Dyer said yesterday council staff were working with Maritime New Zealand to "clarify their expectations for carrying out this type of work in the marine environment".
"The council and the current contractor had agreed the contractor does not have the equipment required for the specialist job.
"DCC staff are working with alternative contractors that have the appropriate Maritime New Zealand certification to ensure the partial removal of the wharf as soon as possible, for health and safety reasons.
"It is likely the work will occur in the second week of January."
