“As far as we know there have been no fatalities, but this could change,” Greg Panagos said.
A BP spokesperson said:"All of BP’s on-board personnel are safe and have been accounted for."
A US Coast Guard statement released earlier today stated that all 126 crew on the semisub had been evacuated. They have been taken to New Orleans for medical checks and treatement, if necessary.
A Coast Guard spokesman said there were some reports of injuries, although the number and severity of these was not yet known.
Unconfirmed reports from Louisiana-based TV station WWLTV said eight people had been critically injured.
The US Coast Guard District Eight command centre first received reports of the incident around 2200 hours local time yesterday.
By 04.20 local time this morning, a Coastguard spokesperson confirmed the fire had not yet been extinguished.
He said the cause of the blaze is not yet known, but an investigation will be carried out.
“Any guesses on the cause of the fire now would be pure speculation,” Panagos said, adding that Transocean's focus at this stage was the safety of its crew.
Coast Guard helicopters, planes and cutters are still at the scene, about 52 miles (84 kilometres) south-east of Venice, Louisiana. The Macondo prospect is in the north Mississippi Canyon area.