The police watchdog is to investigate allegations Metropolitan Police Service (MPS) suppressed evidence and covered up offences relating to child abuse from 1970 to the 2000s.
The Independent Police Complaints Commission is to probe 14 instances of alleged corruption in the London police force after referrals by the Met.
The allegations include claims police suppressed evidence relating to child abuse, hindered or halted investigations and covered up the offences because of the involvement of politicians and police officers.
In one alleged instance, an investigation into a paedophile ring, in which a number of people were convicted, did not take action against other "more prominent individuals". There are also claims that a separate investigation involving a operation targeting young men at the Dolphin Square estate in Westminster was stopped because officers were "too near prominent people".
There are further allegations that a politician spoke to senior Met officers and demanded no action was taken regarding claims boys were "procured and supplied" to a prominent Westminster paedophile ring in the 1970s.
The IPCC is also investigating claims an account provided by an abuse victim had been altered to omit the name of a senior politician.
IPCC deputy chair Sarah Green said: "These allegations are of historic, high level corruption of the most serious nature.
"We will oversee the investigations and ensure that they meet the terms of reference that we will set. Allegations of this nature are of grave concern and I would like to reassure people of our absolute commitment to ensuring that the investigations are thorough and robust."
A Scotland Yard spokesperson said: "The MPS recognised the severity of the allegations, and the importance of understanding whether or not our officers had in the past acted inappropriately, and therefore voluntarily referred the 16 separate allegations to the IPCC.
"Ongoing investigations and recent convictions by officers from the Sexual Offences, Exploitation and Child Abuse Command have shown that the MPS is fully committed to investigating non-recent allegations of sexual abuse."
The IPCC said a further two referrals of a similar nature from the Met Police are still being assessed.