A tiger hunt has begun in North Yorkshire after police received two reports of sightings from members of the public.
The description of the six-foot long tiger is consistent with that of a 12-month-old cub, according to wildlife experts.
Paul Westwood, of Big Cats Monitors, said: "If it is a tiger, when it gets hungry it's going to go for anything that moves. It will be very dangerous."
A farmer and another resident alerted police last Friday to say they had seen the big cat in fields in the Church Fenton area of the county.
Police began a search following the tip-off and phoned local farmers to warn them of the potential danger. The RAF, which already had a plane in the area, were alerted, but there was no sign of the tiger.
Tony Lidgate, a spokesman for North Yorkshire Police, said: "Every year we probably get about a dozen calls from the public about animal sightings, but usually it's panthers or pumas.
"Over the years we've never come across any definite evidence of any big cat. That's not to say they don't exist here, though.
"We would stress that we have no solid evidence that this is a tiger but we advise the public to be vigilant and to report any sightings to us immediately."
Mr Lidgate praised members of the public who alert the police, describing their actions as "responsible". Police but have told local farmers to look out forpaw prints or unusual killings of livestock in the area.
The police have advised the public to not approach any large wild animals they see but to contact officers immediately.