A 30-tonne sperm whale which stranded and died on a Scottish beach may have taken a "wrong turn", experts say.

The 45ft-long mammal was discovered at Monifieth in Angus in the early hours of Wednesday morning and died despite attempts to rescue it.

Scientists from the Scottish Marine Animal Strandings Scheme (SMASS) have carried out an autopsy on the whale and say they found no sign of illness or injury.

The young male was so large they had to use a 22-tonne JCB "like a dissecting scalpel".

SMASS director Dr Andrew Brownlow said: "In general, the animal was in good body condition, with no indications of an entanglement or ship strike.

"The organs were pretty autolysed - sperm whales decompose incredibly quickly once dead - but they didn't show any indication of disease. No significant marine debris or plastic was found either.

"Obviously we will need to wait to see what else we find from our lab analysis, but it is plausible this animal stranded in the Firth of Tay due simply because it made a navigational error.

"Once in shallow waters with large tidal range, animals of this size are at great risk of stranding and doing so is almost always fatal."

Dr Brownlow was forced to climb the 22ft-wide whale to take a blubber measurement from its flank.

The team also removed the whale's head - in what they believe may be a UK first - to study its brain and rule out any neurological causes for its death.