Rick Minter, who has received more than 1,000 reports of people’s encounters with big cats, said the animal was most likely to have been a leopard.

Of the five species in the Panthera genus – lion, leopard, tiger, jaguar and snow leopard – the only other cat that has a similar melanistic form is the jaguar, and they don’t appear to be in the British countryside, he added.

I'm failing to see why that's an argument that favors leopards over jaguars.