A police force has been fined £150,000 after video interviews with victims of violent and sexual crimes got lost in the post.

Greater Manchester police (GMP) sent three unencrypted DVDs containing the sensitive footage to the serious crime analysis department of the National Crime Agency by recorded delivery but they were never received. The DVDs, which showed named victims talking openly, have never been found.

An investigation by the information commissioner’s office (ICO) found that GMP failed to keep highly sensitive personal information in its care secure and did not have appropriate measures in place to guard against accidental loss. This is a breach of data protection law.

Sally Anne Poole, ICO enforcement group manager, said: “When people talk to the police they have every right to expect that their information is handled with the utmost care and respect.

“Greater Manchester police did not do this. The information it was responsible for was highly sensitive and the distress that would be caused if it was lost should have been obvious.

“Yet GMP was cavalier in its attitude to this data and it showed scant regard for the consequences that could arise by failing to keep the information secure.”

The ICO investigation found that GMP had been sending unencrypted DVDs by recorded delivery to SCAS since 2009 and only stopped after the security breach in 2015.

In 2012 the ICO fined the force £150,000 after an unencrypted USB stick was stolen in a burglary at a detective’s home in July 2011. The unencrypted device with no password protection stored details of 1,075 people with links to drug probes, arrest targets and officers’ names.

GMP said it had abided by national guidance and was currently considering its response to the latest fine. Assistant Chief Constable Rob Potts said: “The disks were sent in accordance with national guidance for sending sensitive information, however when it became apparent that the disks may have been lost we immediately reviewed our own procedures and as a result postal delivery is no longer used by GMP for sensitive information.

“I think it is important to stress that when the potential loss did become apparent, we worked closely alongside Royal Mail to do everything possible to try to find the disks and immediately informed the three people concerned in the video interviews.

“They have been kept updated of this ongoing investigation and contacted this week to inform them of the ICO’s decision. We understand that seeing the news of this sanction reaching the public eye may bring back vivid memories of what happened to them and so we are providing them with support from specially trained officers.

“I also think it is important to stress that since this particular incident happened, the national guidance surrounding sending sensitive information has also been amended with the aim of preventing similar occurrences happening in future.

“It is key to our work to protect the public that victims feel safe and assured when coming forward to report crime and I want to make it clear that we will continue to do everything in our power to treat any information given to police in the strictest confidence.

“I would continue to urge anybody who has been a victim of crime to come forward to police, we are here to help and we can provide specialised support so you don’t have to suffer in silence.”