The Crown Prosecution Service (CPS) lost DVDs containing interviews with child sex abuse victims after putting them in the post, it has emerged.
It has been fined 325,000 for the breach, which was the second time it had been punished for the loss of sensitive video recordings.
The Information Commissioners Office said the disks contained interviews with 15 victims who were abused as children, which were to be used at a trial.
The DVDs contained the most intimate sensitive details of the victims, as well as the sensitive personal data of the perpetrator, and some identifying information about other parties, a spokesperson said.
The DVDs were sent by tracked delivery between two CPS offices, with the recipient office being in a shared building. The delivery was made outside office hours, and the DVDs which were not in tamper-proof packaging were left in the reception.
Although the buildings entry doors were locked, anyone with access to the building could access this reception area.
It is not known what has happened to the DVDs.
The penalty came following a series of controversies over the CPS’ handling of collapsed rape cases and false child sexual abuse allegations, amid budget and staff cuts.
The current Director of Public Prosecutions, Alison Saunders, has announced she will be stepping down in October at the end of her set five-year term.
The disks were sent in November 2016 but no one noticed they were missing until the following month, and the CPS did not notify the victims involved until March last year.
The Information Commissioners Office ruled that the CPS was negligent by failing to ensure the videos were kept safe, and did not take into account the substantial distress caused if they were lost.
Despite being fined 200,000 following a separate breach in November 2015 where victim and witness video evidence was also lost the CPS had not ensured that appropriate care was being taken to avoid similar blunders happening again, the watchdog said.
Steve Eckersley, the head of enforcement, said: The victims of serious crimes entrusted the CPS to look after their highly sensitive personal data – a loss in trust could influence victims willingness to report serious crimes.
The CPS failed to take basic steps to protect the data of victims of serious sexual offences. Given the nature of the personal data, it should have been obvious that this information must be properly safeguarded, as its loss could cause substantial distress.
The CPS must take urgent action to demonstrate that it can be trusted with the most sensitive information.
A spokesperson for the CPS, which prosecutes criminal cases in England and Wales, said they had apologised to affected families and offered to meet them face-to-face.
There is no indication the material was viewed by any unauthorised person, she added.
CPS South East have completely reviewed their systems and processes for the receipt and handling of video interviews to ensure that this situation cannot arise again.
The original version of the data was retained by the police and the defendant pleaded guilty in court. He was given a six year prison sentence in March 2017.
The CPS said a new system wasbeing rolled out to allow the secure online transfer of material between the CPS and the police, meaning recorded interviews wouldno longer need to be sent by post.