Police divers are the latest recruits to join the search for Allan 'Martin' Anderson, who is missing from a property north of Inverell.
The divers have been called in to scour dams and other submerged areas, with the Pindaroi man and his dog 'Bet' yet to be found on day five of the search.
The 65-year-old hasn't been seen since last Wednesday.
Inverell police told ACM the search will continue on Monday and Tuesday, with the situation to be reassessed Tuesday afternoon.
It comes after a social media call out on Saturday, asking for skilled horse riders and people on foot to join the search efforts.
Fernlee Station put out information about where to go and who to contact if anyone in the region was in a position to help search for the "greatly loved" man.
The urgent message called for assistance in looking through rugged bushland in less than ideal conditions.
"[H]elp bring this family's most greatly loved father and husband home," the station posted.
Checkpoints were set up on Friday and Saturday at the station.
The station's statement said the continued search on Monday required volunteers on foot, two-wheel motor bikes and horse back, to arrive at "Flaggy" 2293 Pindari Dam Road, Ashford.
A full host of police resources has been dedicated to the search so far, with interstate officers contacted on Sunday.
They were asked to share any information they may have to assist with finding Mr Anderson.
Queensland police were notified, considering Mr Anderson's proximity to the border.
Victorian police were also notified of the situation, as he hails from the state and officials are also considering the possibility he could have returned.
New England police, Police Rescue Squad, PolAir, Police Dog Squad, SES, RFS, and ambulance crews took part in the extensive efforts last week.
Officers on trail bikes, drone operators and local volunteers were also deployed in the search operation.
Last week, Acting Inspector Ross Chilcott said residents should keep their eyes peeled for Mr Anderson's black and tan kelpie 'Bet'.
"If anyone finds a tan and black kelpie dog with a blue collar made named 'Bet', they can help us," he said.
The family hold grave concerns for Mr Anderson, as he suffers from a number of medical conditions.
Mr Anderson is described as being of Caucasian appearance, about 170cm tall, of slim build, with balding, grey hair and blue/grey eyes. He is 65 years old.
Police are now urging anyone who may have seen him or his dog to call Crime Stoppers on 1800 333 000.
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