Scotland Yard will support a public inquiry into claims undercover officers hunted for information to smear the family of Stephen Lawrence, Commissioner Sir Bernard Hogan-Howe has said.
But the Metropolitan Police chief warned the process could be lengthy and inconclusive.
Speaking on radio station LBC, Sir Bernard said: "If you do have a public inquiry, it can take a long time and it's not always conclusive at the end of it.
Secondly, if there is more wrongdoing discovered, it still has to come back to the police or to the IPCC (Independent Police Complaints Commission) to investigate and prosecute.
"A public inquiry can decide who did what, but if you want to get into a criminal prosecution or a misconduct process, it still has to fall back to the police. You might end up having two parallel things.
"I'm content that the investigation has to continue to establish the facts, and if the Government or Parliament decides that it would prefer a public inquiry, then of course we would support that."
Doreen Lawrence has said it will "take a while to gain trust" after she met with the Metropolitan Police commissioner over smear claims.
Scotland Yard has been confronted with another accusation of underhand tactics in its investigation of the murder of Stephen Lawrence.
The father of murdered teenager Stephen Lawrence said he felt "betrayed" by allegations the Met Police tried to smear his family.