Police are searching for a female Russian tourist who was days away from getting married when she swept into the sea while doing yoga on rocks.

Kamilla Beliatskaya, 24, sat at the idyllic Lad Koh viewpoint with her pink foam mat on the island of Koh Samui, southern Thailand, on November 29.

But while Kamilla - who had already taken pre-wedding photos with her partner - was exercising with stretches when a powerful wave slammed into the shore. The forced of the water knocked her over and dragged her from the rocks into the ocean.

Footage from an onlooker shows the moment she was struck followed by her briefly floating in the water. CCTV recovered by police also shows the moment she was dragged away.

However, when rescue teams arrived they could only see her pink yoga mat floating in the surf and the conditions were too dangerous for them to enter the water.

Jet skis, normally rented to tourists on the nearby beach, had also been moved inland due to the choppy sea conditions.

Police Senior Sergeant Major Suporn Hemrangsee said: 'The tourist was caught off guard by the large wave, which was sudden and unexpected.

'Life guards could not immediately enter the water as the conditions were too dangerous.

''The obstacle to entering the sea was the high waves. They were two or three meters high and the conditions were very rough, which may have caused the tourist to lose strength.

'There are warning flags on the beaches during this time of the year. It is not safe for tourists to enter the water. They should not get too close to the sea.'

The officer said the viewpoint had now been closed off to prevent holiday makers from using it to take photographs.

Police eventually dispatched two jet skis to search the stretch of coastline. Rescue teams were also sent out on foot to nearby beaches.

The search was called off at nightfall and resumed on Saturday morning.

Kamilla's boyfriend Grigorii Anokhin said that the couple travelled to Koh Samui every year for a holiday. They were due to return to the motherland in December to get married.

He said: 'On the day of the accident, my girlfriend said she was going to play tennis, but I did not know that she had stopped by to relax at the Lad Koh viewpoint.

'I only found out what had happened from social media. I was devastated and immediately went to the area to help look for her.

'I have been with my girlfriend for five years and we were planning to have a wedding in mid-December.

'We had already taken pre-wedding photos in the hope of living together when we returned to Russia.'

Thailand's unpredictable seas are at their most dangerous in October, November and December when the monsoon season is reaching its peak.

Dozens of holiday makers are killed every year when they are dragged away by the powerful currents.