The sinking of the cruise boat Waverley in Doubtful Sound last week is being investigated by Maritime New Zealand.
Spokeswoman Sophie Hazelhurst told the Otago Daily Times the inquiry would look at what safety lessons could be learned.
A Maritime NZ investigator would interview the boat's skipper, Te Anau-based owners Clint Tauri and John Harris and some of the eight overseas passengers who were rescued without injury, hours before the boat sank.
"Whether or not there will be a report depends on what is discovered," Ms Hazelhurst said.
"If there was a hazard that some action needed to be taken, then a report would be compiled with that recommendation in it."
On Monday , Environment Southland suspended its oil spill response to the sinking of the Waverley, and said there has been minimal environmental impact.
Most of the 700 litres of diesel on board the boat had dispersed or evaporated, regional on-scene oil spill commander Kevin O'Sullivan said.
The Waverley sank late on Thursday night in Doubtful Sound, Fiordland, after earlier striking a rock.
The eight passengers and two crew members aboard were safely transferred before the boat sank near Matai Island about midnight, while being towed.
"Tourist operators in Doubtful Sound will monitor the waters around the submerged boat and if there is any sign that a larger amount of oil is surfacing, or birds are found to be affected, a response can be mounted immediately," Mr O'Sullivan said.
Department wildlife advisor Pete McClelland said that the oil spill from the Waverley proved to be "the best case scenario" that could have occurred in a very sensitive environment.
"The impact on wildlife has proved to be minimal," he said.
