Four Corners on Monday (November 8) investigated over four months whether members of corrupt politician Eddie Obeid's family may have secretly backed controversial coastal property developments, including at the seaside town of Hawks Nest.

While Eddie Obeid and his second son are in jail, the program suggested two of his other sons, Gerard and Eddie junior, may have been involved with plans to build a $100 million, 140 apartment development beachside, next to Hawks Next golf club.

Karuah Local Aboriginal Land Council sold two parcels of land next to the golf club in 2016 for $1.5 million, according to former chief executive officer, Len Roberts, who is now a councillor at MidCoast Council.

The sale was a windfall for the land council which was in financial dire straits at the time, and the figure was double what the land was valued at, he said.

"It's not sacred land," he said. "People often question why Aboriginal people sell land, and the reality is that asking that question is actually racist ... that is saying Aboriginal people should not do what everybody else does."

Mr Roberts said while some people may not have attended the final meeting, there were many meetings leading up to that point and no-one objected to the sale, which involved a board members' vote and a "rigorous process".

Ultimately, it was sold to two companies, Core Property Developments and Leric Group Pty Ltd.

"I know nothing about either of them," Mr Roberts said.

The Four Corners report says Hawks Nest locals fear the golf club luxury apartments development will set a precedent, leading to the development of another parcel of land owned by the land council - a beachfront strip stretching across 270 hectares. But so far it remains in the hands of the land council.

MidCoast Council mayor, David West, said from the council's point of view, the proposed development of luxury apartments was "just a DA".

The Four Corners investigation describes Leric's sole director, Merwin 'Memo' Ibrahim, as a "key figure' in the Obeids' coastal property interests, and a long-standing family friend, with multiple links to developments backed by the Obeid family.

But Mr Ibrahim told the ABC that had never been in business with any members of the Obeid family.

Gerard and Eddie junior did not respond to questions put to them by the program.

Laurus Projects, the developer of another project Four Corners alleged the brothers had backed, told Four Corners that the Obeid family had no involvement.

That project is a $23.5 million apartment development with 68 units proposed for a key site off Pacific Drive near Windmill Hill in Port Macquarie. Gerard Obeid lives next door.

A parcel of land owned by Port Macquarie-Hastings Council and linked to the proposed DA for the site also came under scrutiny.

To the south, the the investigation looked at the Obeid family's backing of the Catarina Estate at Lake Cathie - a significant residential development approved in 2013 that saw a large swathe of prime oceanfront land levelled, divided and sold off as more than 100 land lots.

The 16-hectare property was acquired by Eddie Obeid in 1988 from the late John Abi-Saab, who was the longest serving shire president of the Hastings before moving to Strathfield where he served as mayor.

The program also revealed that David Carroll, CEO of the Birpai Local Aboriginal Land Council, was not aware that Gerard Obeid would be present at discussions in June this year, when approached by a family intermediary about land for future social housing and other possible developments.