The Wadi Alkarm has been docked off Wollongong since Thursday night when 11 crew refused to continue sailing with the company, Egyptian-owned National Navigation Co.

They told Australian International Transport Workers' Federation representatives their wages had been halved and they had been prohibited from accessing food and water between 7pm and 7am daily.

On Saturday, four of the men took the company up on its offer of an immediate flight back home.

But seven of the men have remained and are refusing to leave until they get their wages.

One crew member from Alexandria, Egypt, who did not want to be identified, said company officials had called his mother and told her they would "harm" him unless he flew home or continued sailing with the ship.

"All the crew here are afraid," he said.

"We don't want to work, we want our rights and to go ... to our home in Egypt."

Maritime Union of Australia branch secretary Gary Keane has been in contact with the men since Thursday, and said they were sceptical of a recent promise by the company to have their owed wages paid either today, tomorrow or the next day.

"These guys quite literally have no money in their pockets," Mr Keane said.

An Australian Immigration Department spokesman said the sailors "remained on valid maritime crew visas".

Mr Keane said workers for the company had been involved in a similar industrial dispute earlier this year in Gladstone, and called on the Australian Maritime Safety Authority (AMSA) to do more to make sure companies followed the 2006 Maritime Labour Convention.

An AMSA spokeswoman said the department was "working with the International Transport Workers' Federation and the ship's master and agent in relation to this issue".

"AMSA understands that all the crew in question will be paid tomorrow," she said yesterday.

"[The authority] understands that the remaining seven crew have opted to return to Egypt once payment is received."

She said arrangements were under way to replace the crew necessary for the vessel.