More details emerged from the desperate search for the man who died after falling in the Thames River near Kingston earlier this week.

One eye-witness who witnessed the lifeboat crews responding to the emergency calls described their actions that night as "incredible."

Speaking to the Comet, Beth Sagar-Fenton — a producer for BBC Radio 4 — described how she had been covering the lifeboat crews for her work on Tuesday evening (July 23) when the emergency call came in.

Remarkably, the crews had been conducting training exercises at the time.

"They were taking part in Tuesday night training, so the whole crew were down there at the lifeboat house in Teddington.

"They were doing some team building and training exercises out on the river in the boats and in their full kit.

"Then the bleepers (emergency alarms) went off," the BBC producer described.

Ms Sagar-Fenton went on to recall the stunningly fast and professional response of the crew, just moments after they realized the situation was a genuine emergency.

The way the volunteer crews reacted, she said, was nothing short of incredible.

"It was incredible. The first of the two boats must have responded in less than two minutes, probably closer to a minute.

"The second went a few minutes later. It was just incredible."

Ms Sagar-Fenton paid tribute to the the dedication and professionalism they showed searching for the missing person.

In particular, she highlighted how the crews all work day jobs, before dedicating many of their evenings to the lifeboat service.

"They were amazing, especially because they're all volunteers.

"They all go to training every week because there's always new things to learn or they have to practice different manoeuvres, first aid and so on.

"What really took me aback was how the volunteer team out on a training exercise received the call and straight away just turned into these incredible, highly trained professionals," Ms Sagar-Fenton said.

"It was like listening to the SAS at work — they all know precisely what it is they're doing and that's largely thanks to the RNLI (Royal National Lifeboat Institute) who trained them. They were totally prepared.

"It's a really heroic thing to do and I'm just in awe of them really," she added.

RNLI Teddington Lifeboat Station were contacted for comment.