Canadians have long enjoyed doodling on the face of former prime minister Wilfrid Laurier to make him look like the iconic Vulcan character. But the craze has gathered pace since the death last week of legendary Spock actor Leonard Nimoy at the age of 83.

The Bank of Canada has confirmed that it is illogical but not illegal for Trekkie scribblers to deface the banknotes by adding Spock’s trademark pointy Vulcan ears, sharp eyebrows and bowl haircut to Mr Laurier’s acquiline features. The culprits can therefore expect to live long and prosper with no real danger of getting into Tribble.

But spokeswoman Josianne Menard said in an email to the Canadian Broadcasting Corporation that there were “important reasons why it should not be done” and implied that the practice made a Spockery of the nation.

 “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,” said Ms Menard.

She also warned that although the disfigured notes remain the real McCoy they may not circulate for long because of the risk that some retailers will reject them. So best Klingon if you want to keep one.