Police and his family are renewing their appeal for information from the public to help locate him so they can make sure he is okay.

They hold grave fears for his welfare and say his disappearance is out of character.

It is not know where Mr Cox went after he left his home on Ashwood Road in Owen's Gap at around 7.30am on May 20.

It is possible that he could have made the trip to the Lower Hunter.

Mr Cox was reported missing on May 21 when he failed to return home.

Police conducted an initial land search of the land surrounding his home.

Police also searched the nearby area but found no trace of him.

The 47-year-old father could be travelling in a grey 2011 dual cab tray back Holden Colorado with New South Wales registration number BZZ 44W.

Mr Cox is of caucasian appearance and is between 175-180cms tall.

He has a solid build.

Family and friends of Mr Cox are circulating a social media campaign to raise awareness about his disappearance and appeal for information.

They say someone must have seen him at some stage since he left his home last month.

Anyone who sees Mr Cox or his vehicle are urged to report the sighting.

Call Crime Stoppers on 1800 333 000 or visit nsw.crimestoppers.com.au.