Geoff MacLellan said the fuel was found by the company that is removing the wreck of the MV Miner from Scatarie Island, a provincially protected wilderness area.
MacLellan said the fuel was found in tanks in one area of the vessel and has been removed safely.
On Tuesday, MacLellan said federal reports had estimated there was no fuel left on the bulk carrier and only 6.6 tonnes of asbestos, but the company found 30 tonnes of the carcinogenic material.
MacLellan said the updated information on the amount of materials that have been removed is being forwarded to Transport Canada as he tries to make a case for federal assistance.
"How this happened is very concerning for us," he said. "We built a tender on this and built a timeline based on the (federal) numbers and of course this has been a safety factor and environmental issue."
MacLellan said he has not received a response to date from federal officials.
A spokesman for Transport Canada said Thursday that the MV Miner is not blocking navigation and any concerns about pollution should be forwarded to the Canadian Coast Guard.
"Federal government departments including Transport Canada will continue to provide expertise and advice to the province of Nova Scotia as required," Steve Bone said in an email.
He added that federal officials have not found any pollution at the site.
The MV Miner, a 12,000-tonne, 223-metre bulk carrier, ran aground after a tow line snapped in rough seas during transit to Turkey from Montreal in September 2011.