A Conservative MP’s chief of staff cleared of raping a woman in a parliamentary office said he nearly became the latest victim of a miscarriage of justice because crucial evidence was withheld from his lawyers.

Samuel Armstrong, 24, said his life had been “turned upside down” after he was wrongfully charged with two counts of rape and two of sexual assault.

He was cleared unanimously of all charges by a jury at Southwark Crown Court following a seven day trial. The jury rejected prosecution claims that he forced himself twice on a female the woman after a drunken night at the Palace of Westminster in October last year.

It emerged that the woman, in her 20s, had not wanted to release medical records showing she suffered depression and anxiety. Phone records also revealed that hours after the “attack” she tipped off a tabloid newspaper to try to get a sympathetic account published.

Speaking outside court, Mr Armstrong, from Danbury in Essex, said he had struggled to eat or sleep after being charged in October last year.

“I was innocent,” he said. “Were it not for the fact that crucial evidence was disclosed to my defence team just eight working days before trial, there could well have been yet another miscarriage of justice in this case."