A seven-year-old girl was gored by a stag in Bushy Park as her shocked family posed for photos.
The girl suffered a serious thigh injury and was treated at the scene by air ambulance and paramedics.
She was later taken to hospital to treat her injuries.
According to an eye witness it looked like a red deer, which is largest mammal native to the British Isles can weigh up to 25 stone and reach up to 30 miles an hour.
Assistant park manager Bill Swan said: “This distressing incident is an unfortunate but powerful warning to everyone why it is dangerous to approach stags during the autumn rutting season, and at any time in fact.
“Stags are wild animals, and they are especially unpredictable at this time of year and can act defensively if they are aggravated or feel cornered.”
Park goers are warned not to approach stags, especially during rutting season, with authorities advising people to keep a 50-metre distance in notices across the park and on their website.
Bushy Park has one of the largest deer populations with more than 300 red and fallow deers freely roaming its 1,100 acres.
Deer are one of the main attractions of the park, with many families visiting during half term to see them.
However, the Royal Parks want to emphasise that the deer are wild animals and should be treated with caution.
Adam Curtis, Park Manager for Richmond Park, said: “Just because our deer are in enclosed parks does not mean they are domesticated. Our deer are wild and therefore unpredictable.
“People fail to realise this when they are chasing them with a selfie stick, attempting to feed them or even trying to pet them.”
If you know the girl or the girl’s family please email [email protected]