Dad Mark has been found in the bizarre Tromp family case after series of break-ins in Victorian town.

Missing Victorian man Mark Tromp has been found in the outskirts of Wangaratta near the airport, spotted walking down Greta Road by a passer-by.

He has since been taken to a local police station, as police search for clues as to what happened to the family in the last few days to have them flee their home and split up so dramatically.

Earlier, police announced they were probing three different break-ins in the Wangaratta area in the search for Tromp.

Mark’s disappearance, which baffled both police and the public alike, saw investigators examine break-ins that occurred on Thursday at a local horse club, a football club and the general store.

The back door of each location had been pushed open and food had been taken from one, Fairfax reports.

The news of Tromp being found comes after his son today denied speculation the family were suffering from a shared mental health condition.

Mitchell Tromp, who was on a family holiday with his two sisters and parents when the family bizarrely split and lost contact with their father, claimed reports that the family might be suffering from group delusional schizophrenia were incorrect, Fairfax Media reports.

Since Wednesday, the events leading up to Mark's disappearance have been the subject of much speculation and confusion. Many reports over the last 24 hours suggested little-known group mental health conditions could be the cause of the baffling developments coming to light regarding the family's last moments together.

While an internal document circulated among NSW police suggested the family may be suffering from group delusional schizophrenia, others suggest the case bears the hallmarks of a rare psychiatric condition known as folie à deux.

Folie à deux is a French term, translated to “madness of two”, for an illness that can occur within close-knit families. It is these reports that 25-year-old Mitchell denies.

But Mitchell is yet to paint a clear picture of the events that led to his father's disappearance.

The family left on their technology-free holiday together on Monday last week, with Mitchell deciding to head home by Tuesday morning, boarding a train in Bathurst to make his way back to their hometown of Silvan.

His sisters, 29-year-old Riana and 22-year-old Ella, split from their parents that afternoon, stealing a car and making their way to Goulburn.

The duo then went their separate ways somewhere along the journey. Riana was found in the back of a stranger's ute along the highway, with The Goulburn Post reporting that when the 29-year-old was in a "catatonic” and relatively unresponsive state. She was taken to the local hospital for mental health checks.

Her mother, 53-year-old Jacoba Trump, was found two days after being reported missing on Tuesday afternoon, presenting herself to Yass District Hospital after a local saw her wandering around town.

It is understood Rania and Jacoba are now together under the care of local Goulburn health services.

Monbulk Police Sergeant Mark Knight, who is leading the search and who also knows the family personally, is stead-fast in his belief the family's behaviour this week is out of character and something triggered the events.

“This is just a massive meltdown, I’m sure of it,” he told the Canberra Times. “Something triggered them.”