A Sumatran tiger named Melati was killed by her new mate Asim after the pair were introduced to one another in their London Zoo enclosure.
The Zoological Society of London (ZSL) kept the two tigers in adjacent enclosures for 10 days to allow them to become accustomed to each other. Keepers were able to restrain Asim, but Melati died from the attack.
While things initially got off to a slow start, with both tigers described by the zoo as "cautious", they quickly turned serious and Asim began to get aggressive with his female counterpart.
A meeting between two rare Sumatran tigers at London Zoo had a tragic end when the male animal shocked its handlers and killed his prospective mate.More news: BB&T, SunTrust merger to make nation’s sixth largest bank
They managed to put Asim, 7, back in a separate paddock, but by that time Melati, 10, was already dead.
The zoo acknowledged that while introductions of big cats are always considered "high risk", zoo experts had observed "positive signs" and deemed it to be the "right time" to introduce the pair.
Staff are "heartbroken by this turn of events", the zoo said. It was hoped that he would mate with Melati, the zoo's ten-year-old female Sumatran tiger.
The zoo announced Asim's arrival - whose name means "protector" in Arabic - from Ree Park Safari in Denmark, on January 29. After their keepers saw positive signs, they decided to make the "high-risk" introduction on Friday morning.More news: Huawei says it could take 5 years to resolve hardware issues
The zoo's head tiger keeper Kathryn Sanders said last month: 'Asim arrived yesterday after catching the ferry from France and immediately made himself at home in his new, cosy den.
"Asim is a handsome, confident cat who is known for being very affectionate with the ladies in his life - we're hoping he'll be the flawless mate for our attractive Melati", she said, according to Sky News.
The Sumatran tiger, which naturally lives in the forests and jungles of Sumatra, Indonesia, is now classified as critically endangered and is on the International Union for Conservation of Nature's red list of threatened animals.More news: Dingell's farewell message to America includes dig at Trump