Mexico's president claims he has proof that a mythical woodland elf exists.

The mythical woodland elf (c) Twitter

The mythical woodland elf (c) Twitter

President Andres Manuel Lopez Obrador posted a photo on his social media accounts that he says shows an "alux" from ancient folklore.

The grainy image appears to have been taken at night and shows an indistinct creature in a tree staring down at the camera.

The politician suggested that the creature resembled a sculpture from an archaeological site on the Yucatan peninsula and revealed that it had been taken recently on the site of a new railway line known as the Tren Maya, which will connect ancient Mayan sites.

However, social media users pointed out that Lopez Obrador's photo had been circulating online for the past two years.

One user responded to his post: "If you believe this, you are stupid."

Another added: "It's so easy to Google a photo to see if it's true or not."