The Independent Police Complaints Commission (IPCC) launched a probe last month into information provided to the Macpherson Inquiry in 1998 by ex-Met Police commissioner Lord Stevens.
The watchdog said it was trying to establish if any senior officers failed to provide truthful accounts.
Lord Stevens has denied any wrongdoing.
In an outline of its investigation, the IPCC said in a statement that they were investigating "whether there was a failure of top rank or very senior police officers including, but not limited to, the former Metropolitan Police Service commissioner Lord Stevens to provide full, frank and truthful information on the issue of corruption to the Stephen Lawrence Inquiry in 1998".
The IPCC added it would also investigate why no further response was provided to the inquiry following a formal request to be updated on developments about relevant anti-corruption enquiries.
Lord Stevens was Deputy Commissioner of the Met from 1998 to 2000 while the Macpherson report was being compiled.
The report, which found evidence of institutionalised racism within the force, was ordered following concerns about its investigation into the murder of black teenager Stephen Lawrence, who was stabbed to death in an unprovoked attack by a gang of white youths in April 1993.
In a letter sent to the inquiry in June 1998, Lord Stevens said no officer or former officer involved in giving evidence at the inquiry was under investigation for corruption.
However, a review of the case last year by Mark Ellison QC found corruption allegations about a Met Police detective who worked on the original investigation into the killing should have been revealed to the inquiry.
Following the release of the Ellison review last year, Neville Lawrence complained to the Met Police, which referred itself to the IPCC.
It took more than 18 years to bring two of Mr Lawrence's killers - Gary Dobson and David Norris - to justice. They were found guilty by a jury at the Old Bailey in January 2012, and given life sentences.
An investigation into evidence given to the Stephen Lawrence murder inquiry by a former Met Police chief has widened to include other senior officers.