Daily Mirror published pictures that appeared to show Moss taking cocaine.

LONDON, England (CNN) -- Supermodel Kate Moss will not be charged over newspaper claims that she took cocaine in a London recording studio last year, British prosecutors have announced.

The Daily Mirror published photographs in September of her apparently snorting cocaine in a studio where her then-boyfriend, musician Pete Doherty, was recording with his group Babyshambles.

Moss, 32, attended a drug rehabilitation clinic in the U.S. after the allegations, and was interviewed by police in London on her return.

The Crown Prosecution Service (CPS) said on Thursday there was "insufficient evidence" to proceed with a case against her.

In a statement, Scotland Yard said: "Despite all reasonable enquiries being pursued by the investigation, which included forensic examination of the scene of the alleged drug taking and investigation into the suspected supply network, we have been unable to provide sufficient proof of the identity of the substance depicted in the media photographs.

"It should be noted that this investigation was never solely into the actions of one individual but mainly focused on tracing the wider drug supply."

Rene Barclay, spokesman for the UK's Crown Prosecution Service, told the UK Press Association that footage of Moss's activities could not prove whether the substance was cocaine, ecstasy or amphetamine.

These drugs are in different categories -- Classes A and B -- and therefore the prosecution could not proceed because it was impossible to verify which category of substance was being abused.

"The film footage provides an absolutely clear indication that Ms. Moss was using controlled drugs and providing them to others," he said.

"However, in the absence of any forensic evidence, or direct eye witness evidence about the substance in question, its precise nature could not be established."

"Ms. Moss declined to provide any explanation when interviewed, and the direct eye witnesses also declined to provide evidence.

"Expert analysis of the footage, however, narrowed the possibilities down to three particular drugs: Cocaine, ecstasy or amphetamine.

"But these three substances fall into two different legal categories of controlled drugs.

"To obtain a conviction, case law establishes that the prosecution must prove beyond reasonable doubt the legal category to which the substance being used belonged.

"Proving that it was a substance belonging either to one or other of two different legal categories is not sufficient.

"Accordingly, as the available evidence fell short of establishing the necessary crucial facts, we decided that there was no realistic prospect of conviction and that a prosecution could not therefore be started."

Metropolitan Police Commissioner Ian Blair has vowed to crack down on middle-class users of the drug in London. He said the decision on whether to charge Moss would take into account her effect on "impressionable young people."

CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more.

CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more.