Scotland Yard is probing claims that Special Branch attempted to interfere in an inquiry that would have revealed an MP was involved in child sex crimes.
The allegation is one of 12 new cases of alleged historical corruption relating to the investigation of paedophile activities dating from the 1970s and 2000s, the Independent Police Complaints Commission said.
The new claims being examined by Britain’s largest force are in addition to 17 announced earlier in the year.
They involve allegations that evidence was suppressed, investigations were halted and offences were covered up because of the involvement of MPs, VIPs and police officers.
The IPCC is managing and overseeing the corruption inquiries, which are to beconducted by the Metropolitan Police’s Directorate of Professional Standards.
Most of the investigations have been sparked by allegations made by retired Met officers.
Special Branch featured in three of the latest claims.
One centred on allegations about an attempt in the 1970s to interfere in an investigation that would have revealed an MP to be involved in child sex offences.
Special Branch officers are also said to have taken over an investigation into child sex offences committed by an MP which was then shelved.
Another claim that the section covered up evidence relating to an allegation that a serving Met Police officer was involved in a paedophile ring in north London is being assessed.