Hong Kong's authorities have searched a country park after receiving a call from a couple who claimed to have spotted a tiger in the area.
However police found no trace of the animal, which was described as yellow and 90cm (3ft) long. It is now thought the couple may have seen a leopard cat.
Experts say tigers have not been seen in Hong Kong for more than 50 years.
Leopard cats, which can grow up to about 70cm in length, are found in parts of Asia including China.
The couple called the police on Tuesday morning after they saw the animal on Ma On Shan Country Park. They were escorted downhill by an officer.
"They claimed the animal was yellow in colour and measured about 3 feet by 2 feet. They were worried, so they called police," a police spokesman told the South China Morning Post.
The couple were sent to hospital suffering from shock, Radio Television Hong Kong reported.
The couple were later shown photos of various feline animals – and said a photo of a leopard cat was similar to the animal they saw.
Dr Michael Lau, a director at the WWF's Wetlands Conservation department, told the BBC it was "highly unlikely" that the animal they saw was a wild tiger.
"The South China tiger is probably extirpated from the region, plus the size of the animal is small and if it were a tiger it would be a cub, [meaning that] its mother would be nearby and likely signs of kills would be seen by people," Dr Lau said.
"Hong Kong also no longer has enough space to support tigers. The last substantiated tiger sighting was in Shatin in 1947."
Timothy Bonebrake of the School of Biological Sciences, University of Hong Kong, told the BBC "the likelihood of it being a tiger is close to zero per cent", and added that "leopard cats that are relatively abundant in parts of Hong Kong".
While the South China tiger is considered to be "functionally extinct", the Leopard Cat population is considered stable.
Leopard cats typically have yellow or reddish brown coats with dark spots and streaks, and are nocturnal.