A man suspected of raping a 17-year-old girl was not identified for five years after a Metropolitan Police forensic scientist from Mitcham “caused undue delay” to the investigation, a court has heard.

The alleged victim was no longer willing to cooperate with police by the time of the DNA match following a review of reporting officer Ursula Collins’ casefile in March 2018, a jury was told.

Collins, 43, is on trial at Southwark Crown Court accused of “knowingly neglecting her duties” in eight criminal probes, including five separate allegations of rape, driving whilst unfit, robbery, and a shooting, between 2009 and 2018.

The jury was told one rape suspect had left the country and the Crown Prosecution Service (CPS) had closed the case by the time a DNA match was found after another scientist took over the case.

In another case involving the rape of a 17-year-old girl, a suspect was identified as a result of DNA analysis after a pair of knickers and a sanitary towel, first sent to the laboratory in November 2012, were re-examined following a review of the file in March 2018.

“But at that time – over five years after the complaint was made – the complainant was no longer willing to assist the police,” said prosecutor Deanna Heer KC on Monday.

Collins, from Mitcham, south London, was suspended after the case was discovered and she is on trial at Southwark Crown Court, where she denies eight counts of misconduct in a public office.

Ms Heer described her as a “qualified and experienced” forensic scientist who occupied a “key role” in the investigation of crime.

“She caused undue delay to investigations and created an obvious and significant risk to the integrity of those criminal investigations,” she said.

“The prosecution case is not that Ursula Collins set out intentionally or deliberately to obstruct justice or to pervert police investigations into criminal offences,” she said.

“The prosecution case is that she knowingly neglected her duties as a reporting officer and, in some cases, actively misled other people, in the knowledge that by doing so there was a risk that she would misconduct herself and thereby undermine the integrity of police investigations into crime.”

The prosecutor added: “She knew very well the possible consequences to the administration of justice if she failed to perform her duties properly, the risk that the perpetrator of a crime might not be identified or, indeed the risk that delay would mean that victims would lose faith in the investigation and decline to support it.

“And yet, the prosecution say, she knowingly took that risk.”

In the case of a shooting, a detective asked for a DNA examination of a petrol can and gloves in 2010 in an attempt to identify anyone who had handled them but a match was not obtained until after Collins was suspended in 2018, the court heard.

In another rape case, the DNA profile matching the description of the suspect given by the complainant was found on a pair of leggings, first sent to the laboratory in 2012, only after they were resubmitted for analysis in 2018, the jury was told.

But by then the victim no longer supported the investigation due to the passage of time, said Ms Heer.

The trial continues.