One of the most senior officers in the Metropolitan Police has said it is "a matter of huge regret" that it has taken nearly two decades to bring anyone to justice for the racist killing of Stephen Lawrence.

Tuesday's conviction of Gary Dobson and David Norris for their role in his death comes after an investigation lasting nearly 19 years, during which the force has faced coruscating criticism for the way it handled the probe.

The first investigation into Mr Lawrence's death in April 1993 was lambasted after a public inquiry. Sir William Macpherson's 1999 report of the inquiry's findings called the standard of command in the vital first few hours after Mr Lawrence's killing "abysmal".

He branded the Met Police institutionally racist, and there were allegations by lawyers representing Mr Lawrence's parents that some officers were influenced by the former drugs baron father of David Norris.

Acting deputy commissioner Cressida Dick said: "It's a matter of huge regret to the Met that it has taken 18 years to get to this point."

She went on: "Every homicide case is incredibly important and we seek to bring the killers to justice. This case, which as you know has taken 18 years to get to this stage, is a unique case, not just for the Met but I think in modern policing.

"Firstly because of the horrible, horrible nature of the racist attack, secondly because it's taken so long to come to court in this way and thirdly because of the public inquiry and the very wide-ranging recommendations that came out of that which have transformed policing.

"We were criticised for the way in which the Met investigated in 1993, we've transformed the way we do investigate homicide and I like to think that where we are now exemplifies how we've changed in terms of the way we investigate."

Ms Dick said that the public inquiry was a "turning point" for the force, and that major changes have been made since.

She said that the Stephen Lawrence investigation was "an extraordinary case" and added: "I can't think of another investigation that has had anything like that level of scrutiny and effort over the years. It is truly unique."