Rats that have been mummified in tar for over 600 years could shed new information on the Black Death.

One of the deadliest pandemics in human history, the plague killed vast swathes of Europeans during the 14th century.

And scientists now believe they could be on the verge of a major breakthrough into the strain that caused the epidemic.

They have discovered two mummified rats on a recently excavated shipwreck off Estonia.

According to The Times, they were found to still have a "rat-like appearance" and date back to 1373.

The find is being broadcasted on Channel 4's Bettany Hughes' Treasures of the World on April 13.

Bettany told The Times: "A barrel of tar had fallen over and mummified them, so they have been preserved in tar.

“You don’t get organic material like that preserved from the 14th century. It’s almost unheard of.

"My jaw was on the floor because I was not expecting [the remains] to still look rat-like."

It is hoped the rats will reveal what sailors ate during the Black Death, which could unlock the cause of the disease.