Executives at Canada’s central bank have urged Star Trek fans to stop a campaign to deface currency as a tribute to late actor Leonard Nimoy.

A drive was launched following Nimoy’s death on Friday to ink the features of his most famous character, Star Trek‘s Mr Spock, on five-dollar notes showing a portrait of Canada’s seventh prime minister Sir Wilfrid Laurier.

Large numbers of the notes in circulation now show Laurier with Spock’s pointy ears, trademark haircut and eyebrows, a Star Trek badge and the character’s mantra “live long and prosper”.

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Bank of Canada spokeswoman Josianne Menard has confirmed the stunt is not illegal, but she urges Spock fans to stop.

“It is not illegal to write or make other markings on bank notes…however, there are important reasons why it should not be done,” Ms Menard said in a statement.

“Writing on a bank note may interfere with the security features and reduces its lifespan. Markings on a note may also prevent it from being accepted in a transaction.

“Furthermore, the Bank of Canada feels that writing and markings on bank notes are inappropriate as they are a symbol of our country and a source of national pride.”