The Mail on Sunday reported.
Crosby, who is an Australian, had reportedly told Johnson’s other aides that they should seek more votes from traditional Conservative supporters instead of Muslims, whom he labeled with the swearword.
Crosby’s spokesman has denied that the strategist has used the phrase saying Crosby had “absolutely no recollection” of the incident.
Officials at the Prime Minister’s office have said Cameron has no intention of changing his strategist over the revelations.
The Conservative PM has reportedly signed a £200,000-a-year deal with Crosby and his Crosby-Textor polling company to put them in charge of Conservatives’ election campaign.
Crosby has been named the “Wizard of Oz” for his major success in political campaigns including winning four terms for former Australian PM John Howard.
The man the British Prime Minister has tasked with heading his election campaign is a foul-mouthed anti-Muslim racist who once used the phrase “f****** Muslims” when working for London Mayor Boris Johnson.
Lynton Crosby, whom David Cameron has appointed as his chief strategist, used the outrageous phrase when Johnson’s aides were discussing the possibility of gaining more votes in his mayoral race against Ken Livingstone by wooing minorities especially Muslims,