Amir Khan's sensational win over Mexican boxing legend Marco Antonio Barrera has been made the target of a formal protest, with promoter Don King insisting the fight should have been declared a 'no contest'.

King, who represents Barrera, claims Khan is in possession of a "tainted victory" and he is demanding that the British Boxing Board of Control, the World Boxing Organisation and the World Boxing Association order an immediate rematch.

Barrera was stopped in the fifth round at the MEN Arena in Manchester two weeks ago with his vision restricted by blood pouring into his left eye from a deep gash caused by an accidental clash of heads in the second minute of the bout.

It was not until the fourth round that referee Dave Parris asked a ringside doctor to inspect the wound, which later required 33 stitches. Barrera was told to box on before the same doctor took a second look in the fifth round. This time he advised that the fight should be stopped.

What concerns King is that had the fight been halted prior to the end of the fourth round, the rules state it would have been declared a 'no contest' and Barrera's position in the WBO and WBA rankings wouldn't have been affected.

King said: "Amir Khan is in possession of a tainted victory. The referee and doctor should have stopped the fight immediately after that incredible, accidental clash of heads.

"That they allowed the fight to continue with Barrera competing at a huge disadvantage goes against everything that's designed to protect the health and safety of boxers and the good of the sport.

"Marco Antonio Barrera should not lose any of his position and stature to this travesty of justice. He should not be punished for what was beyond his control.

"He fought like the great Mexican champion he is, with courage and valour, while those charged with ensuring a level field of competition failed the sport and the fighter greatly."

Immediately after the stoppage, Barrera complained that the fight should have been stopped in the first round. He said: "If I'd have had both my eyes then the fight wouldn't have ended this way. I just couldn't see the guy from the first round, the blood was in my eye and I just couldn't see with it."

Dr Allan Fields, chief physician for the Florida Boxing Commission and vice president of the American Association of Professional Ringside Physicians, was in attendance at the match in Manchester.

He believed the inspection by the ringside doctor came late and the contest should have been stopped earlier.

In a statement, Fields said: "I question why the officials waited to make this decision until the fifth round.

"Barrera was visibly impaired by an accident for almost four rounds, placing him at unnecessary risk and certainly contributing to his subsequent decision loss."