Australia's Transport Safety Bureau has delivered its preliminary findings into the grounding of a Chinese coal carrier on the Great Barrier Reef.
The Shen Neng 1 hit Douglas Shoal, east of Rockhampton on 3 April, rupturing a fuel tank and spilling more than two tonnes of oil into the water.
The bureau says the vessel ran aground because its crew neglected to change course as planned. Chief commissioner Martin Dolan says by the time the crew realised they were off course, about 30 minutes later, it was too late, the ABC reports.
Mr Dolan says the results of the initial examination show a variety of factors contributed to the mishap, including the fact that the ship's first mate had only slept for a little over two-and-a-half hours in the previous day-and-a-half.
Investigations found the ship took a short cut several hours before the accident. Mr Dolan says the short cut was reasonable, but several factors contributed to the ship's eventual grounding.
Mr Dolan says the carrier inexplicably failed to turn back on the original course, which would have seen a safe passage through the Capricorn channel.
He says the ship delayed its response for up to half an hour and crew only determined they were closing on Douglas Shoal minutes before they ran aground at a speed of 12 knots.
The ship is now anchored off Barren Island, after it was refloated and moved on Monday night. The bureau will continue to investigate the incident.
Crew members released on bail
Two crew from the Shen Neng 1 arrested on Wednesday by Australian Federal Police over the grounding have been granted bail.
The ship's master and chief officer on watch appeared in the Gladstone Magistrate's Court in central Queensland on Thursday and will reappear in June.
The chief officer on watch has been charged with the more serious offence, of being in control of a vessel that caused damage to the Great Barrier Reef Marine Park.