Three killer whales from a west coast community of orcas have been seen off Peterhead and Girdleness.
A trust which has monitored the group since the 1990s said it was the first time its members had been seen off Scotland's east coast.
Peterhead man Ian Nash videoed one of three on 20 August, the Hebridean Whale and Dolphin Trust (HWDT) said.
Nicknamed John Coe by the trust, the male can be indentified by a notch on its dorsal fin.
It was seen with another male and a female, both believed to be from the same west coast group of whales.
Sanna Kuningas of the Sea Mammal Research Unit recognised John Coe from Mr Nash's footage.
Sea Watch South Grampian co-ordinator Kevin Hepworth also saw John Coe, spotting him close to the beach at Girdleness.
Mark Hosford, HWDT sightings officer, said: "This confirmed sighting - the first in two decades of monitoring this important and highly fragile population of killer whales - is a really exciting development.
"The west coast community is thought to be the only resident population of orca in the British Isles, and understanding their behaviour and movements is crucial to the conservation of these remarkable creatures."
The group, which ranges from the north and west coast of Scotland to Ireland's west coast, is thought to contain just nine older animals.
There are fears that the group will eventually die out after becoming isolated from other killer whale populations.
Peter Evans, Sea Watch director, said: "These confirmed sightings are shattering the idea that there is an exclusively west coast community of killer whales.
"They are clearly ranging further than we had thought, and presumably are seeking out prey in the region."
Sea Watch said John Coe had been seen in a group of killer whales off John O' Groats at the weekend.