The Royal Military Police has apologised to the family of a corporal who took her own life after claiming that she had been raped by two colleagues.
The RMP expressed regret that it had failed to properly investigate the allegations made by Corporal Anne-Marie Ellement.
Cpl Ellement, 30, died at Bulford Barracks in Wiltshire on October 9 2011, two years after alleging that she had been raped while stationed in Sennelager, Germany.
Two former soldiers - Thomas Fulton and Jeremy Jones, both 28 - were acquitted of rape earlier this year following a Court Martial.
The RMP - the Army's internal police force - admitted that "mistakes were made" in the investigation and that "Anne-Marie deserved better".
A statement said: "Corporal Anne-Marie Ellement tragically took her own life in October 2011, two years after alleging that she had been raped by two of her colleagues in the Royal Military Police while serving in Germany.
"The allegation was investigated by the Royal Military Police's Special Investigation Branch, and in December 2009, two individuals were referred to the independent Service Prosecuting Authority.
"However, the prosecutors determined that there was no realistic prospect of a conviction and no charges were brought against the individuals.
"Following the inquest into her death in 2014, Brigadier John Donnelly apologised on behalf of the Army to Anne-Marie's family for the failures in her treatment which contributed to her death.
"The Royal Military Police investigation was reviewed three times and in 2013, following representations from the family, the case was reopened by the RAF Police, assisted by the Bedfordshire Police.
"Subsequently, on October 29 2015, the Director of Service Prosecutions, Andrew Cayley CMG QC, concluded that the prosecution decision in 2010 had been wrong and directed charges against the two former members of the Royal Military Police.
"A Court Martial later acquitted the two individuals.
"The Royal Military Police takes any allegation of rape very seriously. It is now clear that mistakes were made in the original investigation, including in relation to decision making.
"As a result, aspects of the original investigation were unsatisfactory. Any instance where this happens is unacceptable and it is vital that we learn the lessons of these events.
"The Royal Military Police has done so; Anne-Marie deserved better and for that the Royal Military Police apologises unreservedly to the family for those failings.
"In apologising to her family, the Royal Military Police and the wider Army pay tribute to them for the courage and determination that they have shown on behalf of Anne-Marie."
Following the verdicts, Judge Jeff Blackett criticised Fulton and Jones, delays in the case coming to trial and the culture of the RMP at the time.
Judge Blackett described the behaviour of Fulton and Jones, who left the Army in 2014 and 2013 respectively, as "disgraceful".
Cpl Ellement's mother and two sisters welcomed the apology with a "heavy heart", but said it was a "little late".
Alexandra Barritt, Cpl Ellement's mother, said: "Anne-Marie was my beloved youngest daughter. No words can express how much I miss her.
"I will always be incredibly proud of all that she achieved in her life. I hope that the changes the Army have promised us will come about and be a lasting legacy for her."
Sister Sharon Hardy said: "Both the coroner at Anne-Marie's inquest and the judge at her trial made strong criticisms of the conduct of the Royal Military Police men and women involved.
"I know that the RMP failed my sister and am glad that has finally been admitted. I acknowledge the apology offered today with a heavy heart - but it remains to be seen if they have in fact learnt any lessons."
Sister Khristina Swain said: "I feel this apology has come a little late for our family and I'm disappointed we have had to ask for it - but we welcome it and are happy that they have realised they failed to properly protect my sister.
"The RMP let Anne-Marie down 100% - please give her one last bit of respect and don't fail others.
"Don't let victims or families go through what our family went through. Not just the pain and grief - but having to fight just to get to the truth."
Emma Norton, from campaign group Liberty, said the apology comes two weeks after Prime Minister Theresa May and Defence Secretary Sir Michael Fallon pledged to derogate from the European Convention on Human Rights for all future conflicts.
"It is stories like Anne-Marie's that show exactly how important the Human Rights Act is for our soldiers and their families - and exactly why the Government and Ministry of Defence are so opposed to it," she said.
"It was only the Human Rights Act that let Anne-Marie's sisters secure a fresh inquest, exposing the bullying she had suffered and leading to important reforms for crime victims in our Armed Forces. It was only the Act that let them secure a fresh, independent rape investigation.
"Without it, we wouldn't be here today - and the MoD would have been able to keep the awful truth of what happened to Anne-Marie firmly behind closed doors."