An investigation into claims officers from the Met Police professional standards unit abused their position has found no case to answer.
Twenty-one allegations involving eight officers and one member of police staff were investigated by the Independent Office for Police Conduct (IOPC).
Claims included downgrading the severity of charges against an officer.
But IOPC director Steve Noonan said the allegations had been "disproved by the evidence".
It was also claimed that members of the Directorate for Professional Standards (DPS) unit had failed to properly consider the evidence in a case of allegedly racist behaviour apparently being dropped in order to protect the reputation of the force.
Mr Noonan said: "We did establish that the directorate's working practices at the time lent themselves to the possibility of perceptions of prejudice through a lack of communication between officers and a lack of understanding of and adherence to misconduct regulations."
The IOPC said since the investigation the Met had changed its internal processes and now allocated an officer from a dedicated unit rather than from within the team to conduct an investigation.
The allegations were referred to the IOPC in November 2017 and its investigation concluded in July this year.
Met Police Commander Paul Betts said: "We have also improved our record-keeping and trained officers and staff around the importance of this and how to use new IT systems now in place.
"These measures allow us to be far clearer on correct processes to follow, clarify roles and responsibilities and avoid any confusion and misunderstanding by colleagues.
"Our aim is to encourage a culture of openness, transparency and accountability in all our decision-making."