An international ice swimming team who trained in a British lake have won a bucket-fall of medals at the world championships.

The New Zealand team, known as The Frozen Ferns, prepared for the competition in the chilly winter waters of Castle Ashby Lake in Northamptonshire.

The team secured medals across various age groups at the contest in Italy, excelling in the 100m freestyle and 100m breaststroke open final.

Roger Soulsby, the Frozen Ferns team manager, said: “Our top swimmers are churning out 50m laps in under one minute. That’s up there with Olympic swimming.”

The team chose Castle Ashby Lake as their training base due to its near-freezing winter conditions and because the coach at Castle Ashby – David Coleman – is a former New Zealand ice swimmer.

At the sixth International Ice Swimming Association World Championship in Molveno, northern Italy, competitors had to race in water below 5C (41F)

At one stage, the water was -10C (10F) and organisers had to regularly remove thick ice with axes.

Among the standout performances, Emilia Finer won gold and set a new world record in the 200m individual medley.

She described the experience as both a mental and physical challenge, adding: “It was insanely cold, and it’s hard [to get in the ice] every single time, but you can train up your tolerance to stay in for longer periods.

“For shorter races, I come out with a big buzz.”

Mother and daughter duo Charlotte and Heidi Brynn won eight medals between them. Charlotte claimed gold in the 1,000m free and silver in the 500m and 250m frees events.

Heidi earned two golds in the 50m and 100m frees, a silver in the 100m backstroke, and two bronze medals in the 250m free and 50m butterfly.

Her namesake – 16-year-old Heidi Winter – also claimed a 100m freestyle gold.

Her older sister, Sophie, 18, won a 100m gold, while teammate Madeline Hobo, 16, secured two golds and a bronze in the under-18 category.