Prime minister Tony Blair could become the latest VIP to be investigated by chief constable Richard Brunstrom.
Yesterday North Wales police confirmed it was probing a complaint Mr Blair shouted “f***ing Welsh”.
Diaries by former No 10 spin doctor Lance Price alleged the comments were made after Labour’s bad performance in the 1999 Welsh Assembly elections.
Yesterday a spokeswoman for North Wales police said: “A complaint has been received and is now being reviewed.
“We will be seeking the advice of the Crown Prosecution Service in relation to the content of the statement of complaint.”
Asked who made the complaint she replied: “We don’t disclose the names of complainants.”
There were no details of how an inquiry will be carried out, if the force goes ahead with an investigation.
It was not clear if North Wales officers will travel to Downing Street to quiz Mr Blair or his former aide over the allegations.
Last week Mr Brunstrom came under fire from some critics when it was revealed the force spent nearly £4,000 probing “anti-Welsh” comments by acid-tongued Anne Robinson on TV.
No action was taken, although officers went to London to see the BBC’s then-director general Greg Dyke.
Four senior officers were involved in the inquiry.
However the force insisted: “Once a complaint is received North Wales police are duty bound to carry out an investigation.”
Mr Brunstrom’s force made race-hate crime a top priority. In the latest effort to make the public more aware, special leaflets are being placed in takeaway food bags.
Last week Plaid Cymru reported Mr Blair to the parliamentary watchdog Standards Commissioner because of his alleged remarks.