New South Wales Police have scaled back a search for two European backpackers feared drowned off a Port Macquarie beach on the state's mid-north coast.

Key points: The search area in the bay area of Shelly Beach has been expanded

The search area in the bay area of Shelly Beach has been expanded NSW Police said it is still a search and rescue, but it may change to a recovery operation in the afternoon

NSW Police said it is still a search and rescue, but it may change to a recovery operation in the afternoon The Englishman's relatives in New Zealand were contacted and would likely fly over

Englishman Hugo Palmer, 20, and his French companion Erwan Ferrieux, 21, were travelling along the east coast before they were reported missing at the weekend.

Personal items — including towels, sunglasses and car keys — belonging to the tourists were found in their hire car at Shelly Beach on Sunday night.

NSW Police Chief Inspector Mick Alridge said dozens of officers worked in an expanded search area and had a "glimmer of hope" they were still alive.

Hugo Palmer and Erwan Ferrieux were reported missing on Sunday. ( Instagram: Supplied )

However, by the afternoon Inspector Peter Neville said the search had been scaled back and a "very difficult conversation" was had with a family member of the Englishman who flew in from overseas.

"She's very concerned for the member of her family that is missing here," Inspector Neville said.

"It's a very difficult conversation to have sometimes, but we have been very honest with friends and family and have told what has occurred.

Mr Palmer and Mr Ferrieux in 2014. ( Facebook: Supplied )

"We have not completely discounted the chance these men may have survived or something has happened to them other than they have entered the water."

If rescue options are exhausted, Chief Inspector Alridge said the search strategy would shift.

"If we can't find them alive, [we'll look into] where they will be and let's do our best to find them," he said.

Police said two female travel companions of the duo were due to meet with them and were seen at the search site.

Mr Palmer posted to social media about their travels across Melbourne and Sydney. ( Instagram: Supplied )

"It is a difficult situation," Chief Inspector Alridge said.

"The boys have arrived in Australia, it looks like, last November with a group of friends and it's had an impact on them as well."

Mr Palmer had documented his travels with Mr Ferrieux and others across Australia on social media since November 1.

The last post was on February 16 and featured the same silver Commodore station wagon their belongings were found in.

The search for the duo will continue in the morning.