Concerns have been raised about how footage captured by personal cameras worn by police officers is stored.
Four UK forces including the Metropolitan Police use a system whereby video is automatically uploaded onto commercial servers rented by US firm Taser, according to Sky News.
The servers are held outside the UK, leading to questions about whether the video is secure.
Sky News reported that British Transport Police, Staffordshire Police and City of London Police also use the system.
Dr Helge Janicke, senior lecturer in cyber security and forensics at De Montfort University, Leicester, said: "The issue is do you trust them to hold your data?
"Do you trust them to preserve the data and do you trust them to fulfil the commitment they have entered in the service level agreement with you?"
She added: "If you are the cloud provider you will have ultimately some access to that data and you can actually try to interrogate it, and that is where the issue of trust comes in.
"And for police in particular, if it is evidential data, we have to be careful to preserve the integrity in a way that can be scrutinised in a court of law."
According to Sky News there are more than 1,600 Taser body cameras worn by British officers.
Information must remain confidential
Shadow policing minister Jack Dromey called for Home Secretary Theresa May to investigate the security of the footage.
He said: "It is of the highest importance that that information remains confidential.
"We cannot be confident that that is the case at the moment, we do not know where the information is stored, we don't know who can access that information and therefore I will be asking the Home Secretary to make a statement to Parliament when Parliament resumes.
"She needs to act to reassure the public."
The Metropolitan Police issued a statement which claimed the force is "compliant with UK best practice".
It went on: "All data is securely stored in the European Union.
"We ensure body worn video data is kept secure and footage that is not likely to be of evidential value will be removed from the system within a very short time - the current guidance is within 31 days."
The force added that the footage cannot be accessed from the US or by Taser.