23-year-old Gary Tweddle, originally from Reading, has gone missing in Australia's Blue Mountains.
He had been staying in Australia near Sydney for a work conference.
New South Wales Police say the search has now been wound down.
Gary's father David from Berkshire was helping searchers in Australia but says he still does not know what happened to his son.
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Plenty of sunshine for some, but a little more cloud in the east and feeling cold
A dry and sunny afternoon for most, although staying cold.
Most places will have a sunny day, but feeling chilly, with the chance of a little more cloud in northern areas.