A black hole is ‘devouring’ its host galaxy (Picture: Getty)

The oldest ever black hole has been found – and is so massive it’s baffling scientists.

Astronomers have spotted a 13-billion-year-old black hole, from just 400 million years after the Big Bang, which appears to be ‘eating’ its host galaxy to death.

This surprisingly massive black hole – a few million times the mass of our Sun – has challenged scientists’ assumptions on how black holes form and grow as it should not be that big so early on in the universe.

If it grew in the usual way, this newly detected black hole would take about a billion years to grow to its observed size, but has taken less than half that time.

Astronomers had presumed that supermassive black holes grew to their current size over billions of years, but the size of this new find suggests that they might be ‘born big’ or they can eat matter at a rate that’s five times faster than had been thought possible.

The team, led by the University of Cambridge, used the James Webb Space Telescope (JWST) to spot their impressive finding, which is published in the journal Nature.

‘It’s very early in the universe to see a black hole this massive, so we’ve got to consider other ways they might form,’ said Professor Roberto Maiolino.

‘Very early galaxies were extremely gas-rich, so they would have been like a buffet for black holes.’

Similar to all other black holes, it is devouring material from its host galaxy to fuel its growth, but at much faster rates.

The discovery has changed our understanding of how black holes form (Picture: Getty/Science Photo Libra)

The host galaxy, called GN-z11, is about one hundred times smaller than the Milky Way and this black hole feasting on it is likely harming its development.

And speaking of discoveries using the JWST, he added: ‘It’s a new era – the giant leap in sensitivity, especially in the infrared, is like upgrading from Galileo’s telescope to a modern telescope overnight.

‘Before Webb came online, I thought maybe the universe isn’t so interesting when you go beyond what we could see with the Hubble Space Telescope.

The James Webb Space Telescope has already made dozens of outstanding discoveris (Picture: Getty/iStockphoto)

‘But that hasn’t been the case at all: the universe has been quite generous in what it’s showing us – and this is just the beginning.’

The team of astronomers detected this black hole as it could be seen glowing, radiating energy in the ultraviolet range.

The team hope that with further research and telescope observations they will be able to untangle the ways in which black holes might form.

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It’s eating its own galaxy to death.