Detective constables Sharon Patterson, 48, and Lee Pollard, 47, are each charged with three counts of misconduct in a public office between 2012 and 2014.

Patterson allegedly wilfully misconducted herself by falsely representing evidence to her supervisor so that no further action would be taken against a male suspect in 2012.

She also allegedly created a false Crown Prosecution Service document to deceive her supervisor into thinking a decision had been taken not to bring charges against a second male suspect.

Then between December 2013 and January 2014 she created a false statement from a witness and passed it off as genuine, the charge states.

Pollard is accused of removing and destroying four photographs which were “relevant and important exhibits” in an investigation in 2013.

He then allegedly failed to contact the complainant before concluding the investigation as he was directed to do.

In May 2014, during the course of another probe, Pollard allegedly misrepresented evidence to his supervisor for no further action to be taken.

The final charge against him states that he created a false CPS charging document to deceive his supervisors into thinking no further action was being taken in the summer of 2014.

In the investigation involving a 13-year-old complainant, he allegedly failed to conduct relevant inquiries as he was told, and reported that they had a “negative result”.

The officers, who live together in Littlefield Road, Colchester, Essex, appeared at the Old Bailey for a plea hearing.

The defendants, who are on bail, pleaded not guilty to all the charges against them during the hearing before Judge Nicholas Hilliard QC.

Their trial will be heard at the Old Bailey before Mrs Justice McGowan from January 14 2019.