Three killers had their murder convictions quashed after a female police officer tried to hide the fact a jury member in their trial was her son’s girlfriend.

Detective Constable Rebecca Bryant lied about her relationship to juror Laura Jones, and sent texts telling her “don’t tell anyone who you are” during the murder trial in 2016.

The officer’s relationship to Miss Jones, a teaching assistant, was eventually discovered just weeks after Dwayne Edgar, Jake Whelan, and Robert Lainsbury, were sentenced to life in prison for knifing 29-year-old Lynford Brewster to death in Cardiff.

The three men then managed to get their convictions quashed in the Court of Appeal after a High Court judge ordered a retrial, accusing Det Con Bryant and Miss Jones of wasting court time and public money.

Picture of Lynford Brewster supplied by South Wales Police
Father-to-be Lynford Brewster was stabbed to death in Cardiff in 2016 (SWP)

Lord Justice Treacy told the appeal hearing in July last year: “It is crystal clear that this juror should never have sat on this trial and that the assertion of objective bias is fully made out.

“In the circumstances, this trial was fatally flawed and the safety of the convictions is totally undermined.

“The folly of the juror and the police officer have wasted vast amounts of time and cost the public a great deal of money.

“Moreover, the agony for the victim’s family is inevitably prolonged.

“We very much regret that fact.

Lynford Brewster death
Jake Whelan (South Wales Police/PA)

“However, there has not been a fair and proper trial because of the conduct of the officer and the juror and in those circumstances it is our duty to act.”

Text exchanges between the two women before the original trial at Cardiff Crown Court showed Det Con Bryant was aware Miss Jones could be involved as a juror, and also that both women knew Miss Jones worked at the school of victim Mr Brewster’s young nephew.

One text the police officer sent to Miss Jones read: “Remember what I sed (sic) though, as long as you don’t know any of the witnesses that’s fine.

Lynford Brewster death
Dwayne Edgar (South Wales Police/PA)

“Don’t tell any of them who u r to me tho in case they think I’ve told u about it although u know I haven’t xxx”.

Det Con Bryant, who was working as a family liaison officer with Mr Brewster’s family during the court proceedings, initially lied about her relationship with Miss Jones after she was questioned by police, but later admitted the juror was in a long-term relationship with her son.

The officer is still employed by South Wales Police and is due to face disciplinary proceedings.

Lynford Brewster death
Robert Lainsbury (South Wales Police/PA)

Assistant Chief Constable Jeremy Vaughan said: “When issues regarding the original trial came to light, the matter was voluntarily referred to the Independent Office for Police Conduct and has been investigated by the South Wales Police Professional Standards Department.

“Our investigation, which has also been subject of independent review, has not found any evidence that the officer intended to undermine the criminal justice process, and following a formal submission to the Crown Prosecution Service the matter will now be dealt with through South Wales Police disciplinary processes.

“Our thoughts remain with the family of Mr Brewster who we have continued to support throughout this difficult time.”

Edgar, Whelan and Lainsbury were all convicted of murder on Monday following their retrial at Bristol Crown Court, and will be sentenced on March 26.