Story By:  Ana Marjanovic, Sub-Editor: Michael Leidig, Agency:  Newsflash

This is the horrifying moment a tourist posing on a wet rock disappears into fast-moving river rapids after losing his balance.

Holidaymaker Al Rawahi Favvzi Faiz Zaid, 49, from Oman, has been missing for four days after he tumbled head first into the Turkish river.

The shocking clip was apparently filmed by a pal in Galer Duzu in the district of Camlihemsin in the Black Sea province of Rize in north-eastern Turkey on 3rd June.

Due to fast-moving currents, Zaid was sucked down without trace and rescuers scrambled to find him.

In the footage, the victim is seen standing on a boulder in the river as the fast-moving rapids rush around his feet.

He then bends down to wash his hands in the river before straightening his back and looking at the camera.

At that moment, he apparently loses his footing on the slippery rock and falls forwards into the churning river.

His stunned friend continues filming for a few seconds before dropping his phone and apparently trying to find Zaid.

According to local media, a search operation was launched in the immediate land area as rescuers could not enter the dangerous water.

But the search team of 28 people – including divers, coast guard and police -has been unable to find Zaid and the operation is now in its fourth day.