Britain's most senior police officer has been referred to the watchdog over the Met Police's investigation into allegations of a VIP paedophile ring.
Dame Cressida Dick is accused of failing to correct claims that abuse allegations were "credible and true".
The Met Police Commissioner said she will co-operate with any inquiry.
Former MP Harvey Proctor made the complaint after his home was raided during the investigation.
Operation Midland, which began in 2014, saw dawn raids on the homes of Mr Proctor, D-day veteran Lord Bramall who died earlier this month, and the late Lord Brittan following a series of allegations that turned out to be lies.
Carl Beech - then known as "Nick" to protect his identity - falsely claimed he and other boys were raped and tortured in the 1970s and 1980s by prominent members of the establishment.
He is now serving an 18-year prison sentence for 12 counts of perverting the course of justice and one count of fraud.
Mr Proctor claimed Dame Cressida, who was not Commissioner at the time, realised the allegations made by Beech were not "credible and true" but failed to correct them.
The former Conservative MP received a £900,000 settlement from the Met last month.
His complaint, made initially to the Met Police, was passed on to the Mayor's Office for Policing and Crime, which has now referred it to the Independent Office for Police Conduct.