The search for two men missing for four days off South Australia’s Eyre Peninsula has been called off.

Derek Robinson and Tony Higgins left Coffin Bay last Thursday bound for Goolwa in a wooden-hulled fishing boat named Margrel.

They contacted a friend saying they had engine trouble on Friday and were diverting to Kangaroo Island.

The friend heard nothing from them and raised the alarm on Sunday.

The search area expanded over the four days to cover more than 103,000 square kilometres with help from the Australian Maritime Safety Authority, Royal Australian Air Force and Kangaroo Island and Volunteer Marine Rescue.

The search area spanned more than 103,000 square kilometres off the South Australian coast. Photo: SA Police

Eyre and Western Local Service Area Superintendent Paul Bahr said there had been no sign of the men or their boat, with the search wrapping up in waters south of Port Lincoln on Wednesday.

“They have checked every part of that area and have had no sign of the vessel,” Mr Bahr said.

Coastlines around Kangaroo Island, the Coorong and the lower Yorke Peninsula were also searched today without success.

This fishing boat left Coffin Bay but has not been seen since. Photo: SA Police

“That doesn’t mean we are stopping our inquiries; we will continue to speak to every witness that we can find in regards to their dealings with these gentlemen to try and determine what their plans were,” Mr Bahr said.

“If any further information comes to hand we will certainly be reactivating the search.”

SA Police said anyone who finds debris washed up on the coastline is asked to contact 131 444.

–ABC