David Cameron has said a public inquiry into the work of undercover policing will "make sure we get to the truth".
The inquiry was commissioned after a report into the police inquiry into the murder of Stephen Lawrence uncovered evidence of corruption.
The Prime Minister added: "It should have not taken this long and the Lawrence family have suffered far too much."
A senior Met Police officer has been moved from his role following the publication of a report into Stephen Lawrence's murder investigation.
Almost 21 years after Stephen Lawrence was stabbed to death, the Home Secretary has ordered a public inquiry into undercover policing .