Zookeepers say it is with “great sadness” that they announced the death of a beloved big cat.

Female Amur tiger Milla, who lived at Marwell Zoo in Winchester, died unexpectedly during a routine veterinary procedure.

Carrie Arnold, Marwell Zoo carnivores team leader, said: “Milla was an extremely charismatic animal; beautiful, confident, savvy and knew exactly what she wanted.

“She loved laying on her back soaking up the sun.

“She will be deeply missed by her keepers.”

Amur tigers, found in the Russian far east and north-eastern China, are endangered with less than 500 believed to remain in the wild.

Milla, 11, was born at Zlin Zoo, Czech Republic, in July 2009 and came to Marwell in September 2012.

Her mate Bagai arrived in December 2013 and the pair were part of the EAZA ex-situ programme, an endangered species breeding programme.

She eventually gave birth to three healthy cubs Makari, Bailla and Zima in May 2016.

Her death came while undergoing a routine veterinary procedure to fit a new contraceptive implant and have a full health check and vaccinations, the zoo said.

Shortly after being placed under general anaesthetic, she stopped breathing and her heart stopped.

Despite every effort, the vet team was unable to resuscitate her.

Milla had no known underlying health issues but a full post-mortem examination is being carried out.