The new object, designated TMR-1C, has been found in a star forming region in the constellation of Taurus.

It lies at the end of a strange filament of light that suggests it has been flung into space from a pair of newly formed stars.

It is possible that TMR-1C is a planet, possibly two or three times the mass of Jupiter, the largest planet in our solar system.

Alternatively it may be a brown dwarf star, a star that was too small to sustain the nuclear reactions in its core that normal stars need to shine.

The so-called protoplanet is estimated to be 130bn miles from its parent stars. It is destined to drift almost forever in the dark regions of interstellar space.

"If the results are confirmed, this discovery could be telling us gas giant planets are easy to build. It would seem unlikely that we would catch one being flung out of a binary star system unless they were common," said Susan Terebey of the Extrasolar Research Corporation in California.

"The results don't directly tell us about the presence of any Earth-like planets," she adds, "but we believe gas giants do influence the formation of much smaller rocky planets."

The runnaway planet was discovered accidently while astronomers were studying images of newly formed protostars in a stellar nursery in Taurus.

It is thought that the planet was once in orbit around one star that was itself part of a two-star system. Somehow because of the gravitational interactions between the three objects the planet got ejected into space.

According to Dr Ed Weiler of NASA, "If the planet interpretation stands up it could turn out to be the most important discovery by Hubble in it's eight-year history."