Boris Johnson says he "certainly thinks the arguments for a judge led inquiry are powerful and interesting."
The Mayor was responding to calls from Stephen Lawrence's father for an independent judicial investigation into claims an undercover officer tried to smear the family shortly after Stephen was murdered.
Mr Johnson said the MPA needed to look at the calls but he added there are counter arguments.
The Mayor said there may also be a case for Tom Windsor from the HMRC to accelerate what he is already doing to look into this.
More top news
Police have released CCTV footage to try to track down a gang who robbed two teenagers of their bikes and mobile phones.
An 18-year-old man has become the first person to be convicted following a night of what police describe as "disorder" in Hyde Park.
Protesters are staging a beach party outside the French Embassy to campaign against a ban on burkinis on some French beaches.