Magawa, the famous mine-clearing rat who was awarded a gold medal for his heroism, has died at the age of eight.
In a five-year career, the rodent sniffed out over 100 landmines and other explosives in Cambodia.
Magawa was the most successful rat trained by the Belgian charity Apopo to alert human handlers about the mines so they can be safely removed.
The charity said the African giant pouch rat "passed away peacefully" at the weekend.
It said Magawa was in good health and "spent most of last week playing with his usual enthusiasm". But by the weekend "he started to slow down, napping more and showing less interest in food in his last days".
Bred in Tanzania, Magawa underwent a year of training before moving to Cambodia to begin his bomb-sniffing career. There are thought to be up to six million landmines in the South East Asian country.
Trained to detect a chemical compound within the explosives, Magawa cleared more than 141,000 square metres (1,517,711 sq ft) of land - the equivalent of 20 football pitches.
He weighed 1.2kg (2.6lb) and was 70cm (28in) long. While that is far larger than many other rat species, Magawa was still small enough and light enough that he did not trigger mines if he walked over them.
Magawa was capable of searching a field the size of a tennis court in just 20 minutes - something Apopo says would take a person with a metal detector between one and four days.
In 2020, Magawa was awarded the PDSA Gold Medal - sometimes described as the George Cross for animals - for his "life-saving devotion to duty". He was the first rat to be given the medal in the charity's 77-year history.
The rat retired last June, after "slowing down" as he reached old age.
"All of us at Apopo are feeling the loss of Magawa and we are grateful for the incredible work he's done," the charity said in a statement.
His "amazing sense of smell" allowed "communities in Cambodia to live, work, and play; without fear of losing life or limb", it added.
Apopo has been raising its animals - known as HeroRATs - to detect landmines since the 1990s.