The event, known as a quasar, took place when the universe was only three billion years old, a crucial time in its history when star formation was at its peak, helping shape the galaxies of today.
Researchers used a group of ground and space-based telescopes to discover the phenomenon in spectroscopic data.
The findings were published in the Nature science journal on Wednesday.
“We don't see a lot of double quasars at this early time and that's why this discovery is so exciting,” said Yu-Ching Chen of the University of Illinois at Urbana-Champaign, the US.
“Knowing about the progenitor population of black holes will eventually tell us about the emergence of supermassive black holes in the early universe and how frequent those mergers could be.”
In 2019, an image of a black hole was captured by scientists for the first time. It was photographed in the Messier 87 galaxy, 55 million light years from Earth.
It had a mass of more than six billion times that of the Sun and the picture helped to prove astronomers’ theories about black holes.
The black hole's magnetic field was revealed two years later in another image.
Researchers captured the massive object in polarised light — helping to reveal magnetic fields on the edge of the black hole.
The observations could shed light on how the distant galaxy is able to launch energetic jets from its core.
The black hole merger that was recently captured could help unlock more of their secrets, including how they form.