A grey wolf killed by a Utah hunter may have been Echo, a female who attracted national attention after wandering through several states to become the first of the protected animals seen at Arizona’s Grand Canyon in 70 years, officials said.

The hunter, who was not named by authorities, told Utah wildlife officers that he accidentally shot and killed a wolf equipped with a radio collar near the Arizona border after mistaking it for a coyote.

Wolves in Utah are protected under the US Endangered Species Act, which bans killing of imperilled animals without a special permit, but coyotes in the state may be shot on sight.

The incident, which is coming under sharp criticism by conservationists, is being investigated by federal and state conservation officers as a possible violation of US and Utah wildlife laws, authorities said. Information gleaned from the radio collar shows the wolf killed in Utah was a three-year-old female that was captured and collared in January in northwest Wyoming, said Utah Division of Wildlife Resources spokesman Mark Martinez.

The wolf spotted near the northern rim of the Grand Canyon in October was also a young female, which had apparently roamed hundreds of kilometres south from the Northern Rockies, according to an analysis of droppings near where she was seen. It may be weeks before additional testing reveals whether the wolf killed in Utah is the same one, which was nicknamed Echo in a contest.

Echo was the first grey wolf seen in the Grand Canyon since the 1940s, when the last wolf there was killed as part of an extensive eradication campaign, said Chris Cline of the US Fish and Wildlife Service.

The grey wolf is protected under the US Endangered Species Act in most states.