The case of an innocent student put on trial for rape because police withheld evidence is just the “tip of the iceberg”, senior barristers said last night.

Liam Allan was charged with 12 counts of rape and sexual assault but his trial collapsed after police were ordered to hand over phone records.

‘Sheer incompetence’ by police meant that texts about an alleged rape victim’s fantasies of violent and casual sex were kept secret and an innocent student was put on trial after two years on bail, a prosecutor revealed today.

The CPS is also being asked to explain why it did not demand full disclosure of evidence including phone records before the trial started.

40,000 text messages revealed the alleged victim pestered the undergraduate for ‘casual sex’.

the woman asked Mr Allan for casual sex and fantasised about rough and violent intercourse and even being raped despite telling police she didn’t like being intimate with men.

He told the BBC his life had been “torn away” by the process, which included being on bail for two years.

Mr Allan’s lawyer Simone Meerabux said it had been “a very traumatic experience” for her client.

She said it was “amazing” the case had got to the stage it did “but it’s not uncommon” because of problems with disclosure.

A Met spokesman said the force was “urgently reviewing this investigation and will be working with the Crown Prosecution Service to understand exactly what has happened in this case.

“The Met understands the concerns that have been raised as a result of this case being dismissed from court and the ongoing review will seek to address those,” he said.