Mr Walker, who has now left South Yorkshire Police, denies all allegations of misconduct made against him in relation to the Rotherham child sexual exploitation (CSE) scandal which engulfed police and social services in the town in South Yorkshire.

These allegations also involve allegations that he failed to register concerns expressed in a series of emails from Jayne Senior, who ran the Risky Business youth project in Rotherham.

The emails contained information that a teenage girl was raped by a man in the presence of an accomplice, a suspect threatened young girls with a gun he was carrying in his car, and a man arrested for sex offenses encouraged girls as young as 10 to visit his house.

Opening the case against the former detective, Daniel Hobbs described how Mr Walker was in charge of Rotherham’s Child Abuse Investigation Unit between 2008 and 2012.

Mr Hobbs told a group of three how Mr Walker had been told by a uniformed neighborhood officer how he had met a drunken 15-year-old girl whose mother had told him about her concerns about her daughter and her 13-year-old sister.

The concerns involved the girl forming relationships and having sex with grown men working at a car wash in Rotherham.

Mr Hobbs told the hearing that Mr Walker ‘did nothing with that information’.

The attorney said the former officer did not record the information, interview any of the girls, or investigate further with the officer who first reported the concerns.

He said a file written by Mr Walker said: ‘This appears to be a social services matter. Please liaise and finalize.”

Mr Hobbs said the officer continued not to investigate despite knowing more about the girls’ vulnerability.

He said a social worker said one of the sisters was the “highest risk case she had ever dealt with”.

The hearing also heard allegations that Mr Walker failed to act on information from Risky Business that a youth worker at Rotherham Council was passing on the names of vulnerable girls he had met in the course of his work to potential abusers.

Mr Hobbs told the panel: ‘Detective Sergeant Walker did nothing at all with respect to this information and simply left any safeguard action arising from social services.

The lawyer said the third allegation related to the series of emails Ms Senior sent him which he did not record.

He said: “Some of these emails contained serious information about rapes, historical rapes and people driving with guns in the trunk of their car.”

Mr Hobbs said at the opening of the case that Mr Walker would argue that non-family child abuse fell outside the remit of the Rotherham Child Abuse Investigation Unit which he heads .

He said the former officer would also argue that he had not been properly trained on CSE matters and was under-resourced.

Mr Walker is one of 47 officers and former officers who have been investigated by the Independent Office for Police Conduct (IOPC) following the Rotherham child sexual exploitation scandal.

The Jay Report, in 2014, described how at least 1,400 city children had been groomed and abused by gangs of men between 1997 and 2013 and described how police and social workers were not not intervened.

Of the 47 officers, eight were found to have a misconduct case to answer and six had a gross misconduct case to answer, the IOPC Fund said.

Five faced penalties ranging from management action to a final written warning, with Mr Walker’s case still pending.

A full report on the findings of the IOPC Fund’s investigation is expected to be published following this hearing.

Last year the watchdog released a ‘Learning and Recommendations’ report which said police needed to listen to survivors of the Rotherham CSE scandal if they were to learn from the past.

The misconduct hearing has been adjourned until March 21, when the panel will begin hearing evidence