Dozens of wallabies that have been found living in the wild in a forest just outside Paris could be the descendants of a small group of the marsupials that escaped from a zoo over four decades ago.

The Telegraph reported on 26 July that around 150 of the animals are now living in the forest of Rambouillet near Paris, where locals had often mistaken them for kangaroos, which look similar but are far bigger.

It is thought the wallabies are the descendants of a handful of the creatures that escaped from a zoo in the 1970s. The existence of the animals had been a well-kept secret until naturalists and animal enthusiasts began coming to the forest to photograph them.

"People knew but didn't say anything," Stephane Walczak of the Ile-de-France Hunters' Federation told the newspaper.

The undergrowth provides them with abundant food, berries, buds and shoots - Laure Raad

"Around a decade ago, locals say someone erected a sign on a road near the forest that said 'Attention: Kangaroos may be crossing' but that passers-by had always thought it was a joke."

The original wallabies are thought to have escaped from the Sauvage Zoological Park near the village of Emance through a hole in the fence. The lifespan of a wallaby is between 12 and 15 years, so the current forest-dwellers could be their grandchildren or great-grandchildren.

The Rambouillet Forest Research Centre estimates there is now a "mob" of between 100 and 150 wallabies living in the forest and they are now being studied to see how the animals have adapted to the French countryside.

But Laure Raad, a research student working on the project, said the habitat is similar to the wallabies' native Tasmania. She said: "The undergrowth provides them with abundant food, berries, buds and shoots."