Adventurer Bear Grylls is facing a possible fine in Bulgaria over an episode of his Running Wild series in which he killed a frog and boiled it on a camping stove.

In the episode filmed in Bulgaria’s Rila mountains in 2017, Grylls and US Latin and ballroom dancer Derek Hough were shown killing, gutting and cooking the frog before swimming across a lake.

"It is evident from the film material that during the shooting there were breaches to the regulations and rules of conduct in protected areas: entering and swimming in the water basin of the Karakashevo lake, lighting a fire, and catching and killing an animal," the environment ministry said in a statement.

The series’ production company faces a possible fine of between 500-5,000 euros (£435-£4,350) while Grylls and Hough could receive fines of between 250-2,500 euros.

The Rila national park in southwestern Bulgaria is the country’s largest.

It is a protected area and the ministry said the crew had been briefed on what they could and could not do during the shoot.