North Wales Police have apologised to a journalist for wrongly accusing her of making offensive remarks on television.
Allison Pearson was not on Question Time on the night in question
Daily Mail columnist Allison Pearson received a letter from the force about a complaint that she referred to "little Welshies" during an appearance on BBC One's Question Time.
But Ms Pearson, who is Welsh, did not appear on that particular programme.
North Wales Police said it acted on information provided by the public and the BBC, and was sorry for the mistake.
Ms Pearson wrote about the letter in Wednesday's Daily Mail, after a chief inspector she identified as R Brough from Caernarfon wrote to say they had received a complaint about her reference to "little Welshies" during BBC1's Question Time on 23 February.
The letter continued: "North Wales Police do not believe that your remarks were in contravention of the criminal law, but nevertheless, would like to make you aware of how they were perceived by a member of the public in north Wales."
Ms Pearson wrote: "a) I did not appear on Question Time on 23 February.
"b) I am Welsh and proud to be so. How likely is it that I would be guilty of inciting racial hatred against myself?
"c) Do you take this much care checking the facts in all your cases?
Richard Brunstrom's force has been criticised for similar investigations
"d) What is the going rate of compensation for mistaken identity?"
A police spokeswoman said they received a complaint from a member of the public regarding comments made by a female journalist on Question Time.
The complainant contacted the BBC and claimed to have been told the journalist concerned was Ms Pearson.
'In good faith'
The spokeswoman added: "We now understand that Miss Pearson did not appear on the programme and apologise to her for the mistake.
"An officer made several attempts to contact Miss Pearson yesterday and an apology was left on her answering machine together with a contact number, but she did not return our calls.
"North Wales Police acted in good faith based on the information provided by the complainant and the BBC."
Police have been criticised for pursuing similar cases in the past.
Anne Robinson's comments were investigated in 2001
Last year, the force launched an investigation into alleged anti-Welsh swearing by Prime Minister Tony Blair, following claims by a former Downing Street spin doctor.
Lance Price claimed in his memoirs that Mr Blair repeatedly swore about the Welsh when Labour won only 28 seats in the 1999 Welsh assembly election.
Mr Price, who was interviewed for two hours in London by a North Wales Police chief inspector, said: "I thought it was an extraordinary waste of public money."
In 2001, four senior officers spent 96 hours investigating comments made by TV presenter Anne Robinson on her show The Weakest Link.
The force claimed they received complaints after the Liverpool-born presenter referred to the Welsh as "irritating and annoying".
The investigation - which cost £3,800 and resulted in no charges - was described as "political correctness gone mad" by former Conservative AM Peter Rogers.