A boomerang stolen from a local museum was returned by the same tourist who took it 25 years ago.

The artifact was put on display at Mt. Isa's Frank Aston Underground Museum, which is now closed. It was taken by an American tourist whose guilt urged him to return it, complete with an apology.

"I removed this back in 1983 when I was younger and dumber," said the note, as quoted by BBC News. "It was the wrong thing to do. I'm sorry, and I'm going to send it back."

The note was merely signed, "Peter."

Along with the note came a check donation for the museum.

Mt. Isa Mayor Ron McCullough confirmed that the artifact actually was genuine, having battle marks to testify that it was indeed real.

"Nobody had any knowledge o it being stolen at all until it arrived back," McCullough told The Herald Sun.

"We might write a letter to the gentleman thanking him for his pang of conscience," revealed McCullough.

The sender's full name and address were found on the envelope.