Egypt won’t release the massive container ship that blocked the Suez Canal for nearly a week in March until its owners agree to pay as much as a billion dollars in compensation, according to local authorities, as they investigate how the Ever Given got stuck and shut down one of the world’s most important waterways. “The vessel will remain here until investigations are complete and compensation is paid,” Osama Rabie, chairman of the Suez Canal Authority, told state television in Egypt on Thursday.

“We hope for a speedy agreement,” he said. “The minute they agree to compensation, the vessel will be allowed to move.” Mr. Rabie didn’t say Thursday what amount Egyptian authorities were seeking as compensation. But he said last week that Egypt would demand $1 billion for the cost of the operation to free the ship, the loss of transit fees—an important source of foreign currency for Egypt—and other costs from the blocking of the canal, which caused a traffic jam of more than 400 ships on either side of the channel.

The Suez Canal Authority hasn’t said how Mr. Rabie arrived at that figure, including how much it spent to free the vessel. The blockage cost the Egyptian state $95 million in lost transit fees, according to an assessment by Refinitiv, a financial analysis firm in London. But Egyptian officials also said they would recoup the lost income when they restarted traffic through the canal.

Accidents involving large container ships can cause property claims of over $1 billion, according to credit rating agency Fitch Ratings. Insurers covering the Ever Given will face claims over losses related to perishable goods and supply-chain disruptions and from the Suez Canal Authority for loss of revenues, Fitch has said.

Mr. Rabie has said he wouldn’t rule out a lawsuit, but prefers to settle the matter of compensation outside of court.