South Wales Police has joined forces with Greek authorities to find out what happened to a man who went missing on the Greek Island of Zante six weeks ago .
The family of John Tossell are adamant that a criminal investigation should be opened into his disappearance.
And it is understood that a judge in Greece will this week hear the case for opening a criminal investigation.
The 73-year-old from Bridgend had gone for a walk to the monastery on Mount Skopos near the village of Argassi in Zante on Monday, June 17, but did not return.
"There is just something that we don't know, people don't just go missing like that," said John's daughter, Katy Tossell.
"His age is 73 but he is like a 40 year old, he goes for walks all the time and he swims three times a week.
"It is so frustrating not knowing, it has been six weeks and there is no sign of him, that just doesn't happen," said Katy.
A spokeswoman for South Wales Police has confirmed that officers are assisting Greek authorities with their investigation into John's disappearance.
The family is appealing for anyone who was in the Argassi area between 10 am and 12 pm June 17 to come forward if they saw any "odd behaviour".
The last confirmed sighting was at a café near the monastery around 3pm on the day he went missing.
His daughter Katy and son Gary flew out to Zante at the time to be with their mother , Gillian Griffiths, and assist with the search.
They were also joined by a Welsh mountain rescue team on June 28, who carried out a search of the mountain as they have experience working with that terrain.
Unfortunately, after an unsuccessful week searching the area, the six members of Western Beacons Mountain Rescue called off the search.
Katy said that this confirmed to the family that something 'untoward' has happened to her father.
"He is not on that mountain, or on the road that leads to it, he is nowhere in that area.
"We are convinced that something has happened."
Katy understands that her father's case will be brought to a judge in Greece this week, where they will decide whether a criminal investigation should be launched into his disappearance.
