A fatal welding fire ignited in an area of a Newfoundland tanker that was not tested by a marine chemist for flammable fumes, the Transportation Safety Board of Canada has confirmed.

The flash fire aboard the MV Kometik on April 8 claimed the life of Wayne Dalton, a 38-year-old Cape Broyle resident. Another man was sent to hospital with severe burns.

• FROM APRIL 10, 2006: Investigators probe fatal tanker fire

A flash fire aboard the MV Kometik in April claimed the life of a welder. (Rod Etheridge/CBC)

The Kometik, which services the Hibernia oil field, was moored at Conception Bay at the time of the fire.

The TSB said a marine chemist had been on board the Kometik before the incident. However, the chemist did not test the ship's tank No. 5 to make sure it was clear of flammable fumes before work begain inside the tank.

"Right now, what we know is that the chemist that tested tank No. 4 didn't test tank No. 5," said Pierre Murray, one of five TSB investigators working on the case.

Murray says tank was tested a member of the ship's crew before the welding work began.

The TSB is now examining whether that crew member was qualified to perform that test.

"We have to go through all [the] regulations, all the standards, all the process and look at all that documentation, and come out and say 'Well, what is a competent person to do the job?' " Murray said. "And it's not clear."

Canship Ugland, the company that owns the Kometik, is not commenting while the TSB investigation is still underway.

Meanwhile, investigators are also checking the testing equipment to see if it is working properly.