A British wildlife student has died after being bitten by a deadly black mamba.

Nathan Layton, 27, of Wing, Buckinghamshire, England, was attacked by the snake as he walked in long grass with a group of teachers and fellow students during a trip to South Africa.

His girlfriend, Laura Woolley, was reportedly with him at the time of the bite.

She could only watch on in horror as Layton fell into a coma, from which he never recovered.

The black mamba is the second largest venomous snake in the world and among the deadliest, capable of reaching up to 14 feet in length.

Each snake carries up to 20 drops of venom in its fangs.

As little as two drops of venom would have been enough to have killed Layton.

His family are now arranging for his body to be flown back to Britain.

His aunt, 46-year-old Jacqui Edwards, paid tribute in the Sun newspaper to "a loving, caring person with such a warm heart."

"We are aware of the death of a British national in South Africa and we are providing consular assistance," said a spokeswoman for the Foreign and Commonwealth Office.