A Metropolitan Police review triggered by an illegal rave in Croydon that led to a 15-year-old's death has concluded the force must improve, but has not recommended disciplinary action for any officer.

The internal inquiry, following a rave at a disused Royal Mail sorting office that descended into violent chaos, cleared an officer who received a tip-off about the event of misconduct but ordered changes to the way police handle information.

Kensington schoolboy Rio Andrew collapsed at the event in Cherry Orchard Road in the early hours of June 15 and died the next day.

Around 2,000 people swarmed into East Croydon for the rave, with some lobbing fire extinguishers and masonry at police officers in riot gear. 

It later emerged that a police officer, described by the former borough commander Dave Musker as "quite junior", had received information two weeks earlier about a rave at the building but did not act upon it.

The force today said the officer would not be subject to disciplinary action, but it said it had implemented recommended changes "to the way rave intelligence is recorded, researched and disseminated".

Commander Simon Letchford said: "Whilst the review did not identify any disciplinary or misconduct issues for any of the officers or staff involved, we have recognised the need to improve the way we handle information and intelligence that could relate to illegal raves.

"As a result, we've made changes to the way rave intelligence is recorded, researched and disseminated.

"We've put in place new processes within our intelligence units to ensure that any rave intelligence is continually monitored and reviewed, so that we're in a better position to either prevent or respond to an illegal rave in London.

"Local officers have also been briefed about the signs they should be looking out for and about the importance of properly recording any information relating to raves on our intelligence systems."

Police have arrested 28 people in connection to the rave, on suspicion of offences including violent disorder, money laundering, criminal damage, possession of class A drugs and affray.

Commander Letchford said: " As I've said before, these types of illegal raves are extremely dangerous, and it is the people that are organising these events, and making a lot of money, that are putting people's lives at risk.

"I want to make it absolutely clear that we will do all we can to prevent illegal raves like these from taking place in London and where they do happen, we will look to investigate, identify and prosecute those involved in organising these events."