London, Oct.16 : A huge growth in internet telephone traffic is jeopardising the capability of police to investigate almost every type of crime, including terror-related ones.
Senior sources have told The Times that as more and more phone calls are routed over the web - using software such as Skype - police are losing the ability to track who has called whom, from where and for how long.
The key difficulty facing police is that, unlike mobile phone companies, which retain call data for billing purposes, Internet call companies have no reason to keep the material.
British Home Secretary Jacqui Smith on Wednesday outlined plans for expanding the Government's capability to access data held by Internet services, including social networking sites such as Facebook and Bebo, and gaming networks.
The move follows growing concern among police and the security services that serious criminals and terrorists are using websites as a way of concealing their communications.
At present security and intelligence agencies can demand to see telephone and e-mail traffic from communication service providers, such as mobile telephone companies.
But rapid expansion of new providers, such as gaming, social networking, auction and video sites, and technologies, such as wireless Internet and broadband, present a serious problem for the police, MI5, Customs and other government agencies.
Communications data is now a key weapon in securing convictions of both terrorists and serious criminals. It also plays a central role in investigations into kidnappings and inquiries into missing and vulnerable people.
In the Metropolitan Police service alone last year, 54,000 applications were approved for officers to have access to communications data including to whom and when a phone call, text message or e-mail was sent - but not the content.
A total of 650 applications concerned investigations into tracing missing or vulnerable people.
Overall there were 519,260 requests for communication data last year with the vast majority coming from the intelligence services, police and other law enforcement organisations, such as the Serious Organised Crime Agency and HM Revenue and Customs.
Under Ms Smith's plans, police and the security services will not be able to access the content of the communications but will know each website visited, and to whom and when a phone call was made or a text message or e-mail was sent.
If this raises suspicions, ministerial approval can be sought to intercept what is being sent and read the content.
Smith gave warning that the alternatives to more electronic data being stored would be expensive and invasive.
The Times has learnt that police chiefs are to begin a discreet lobbying exercise in favour of the new powers.
Opposition MPs and privacy groups have termed the step as Orwellian.