A killer whale that died after stranding in Shetland had recently lost her calf, scientists say.

The lone orca was found dead on the shoreline of the uninhabited island of Linga last week.

A post-mortem has now shown the 17ft-long whale was probably alive when it stranded.

It also revealed that the orca had recently been pregnant and likely lost her calf before stranding.

A spokesman for the Scottish Marine Animal Strandings Scheme, whose scientists carried out the post-mortem, said on Thursday: "This was an adult female, 5.2m in length, found stranded on the island of Linga last Thursday.

"Thanks to the help from local residents and some of our volunteers, the carcass was recovered to mainland Shetland and we were able to post-mortem her yesterday.

"She was in a good body condition, she hadn't recently eaten but had traces of hair, likely seal fur, in the intestines."

He added: "Unfortunately the carcass wasn't the freshest and she'd probably been dead a few days before discovery.

"She had a generalised infection in her abdomen, affecting the stomach, kidney, liver and intestines.

"Given her otherwise good body condition, we think this was a relatively acute event and from patterns in the lung and bruising, we are fairly confident she live-stranded.

"She had also recently been pregnant, but was found with a prolapsed uterus and had probably lost her calf prior to stranding. There was no indication of any human-induced trauma or entanglement."

Killer whale strandings are relatively rare in Scotland.

Concerns have been raised over the future of orcas living on the west coast following the death of a killer whale in the Inner Hebrides in January 2016.

Scientists believe there may be just eight orcas remaining in her pod, which is the only killer whale community native to British waters.