An interactive map offering detailed crime statistics on every street in England and Wales appeared to crash hours after its launch.
Users in London, Yorkshire and Manchester were unable to access the detailed online map.
Those attempting to visit the site, http://maps.police.uk/, were shown an automated message saying it was temporarily unavailable.
The teething problems surfaced as Home Office minister David Hanson officially unveiled the website during a visit to a regeneration project in south west London.
He was joined by National Policing Improvement Agency (NPIA) deputy chief executive Steve Mortimore, whose colleagues drew up the map.
The website aimed to offer members of the public unprecedented access to information about crimes taking place in their neighbourhood.
The national map follows on the heels of regional versions created by the 43 forces across England and Wales.
The sites have been widely regarded as a success with some registering more than 50,000 visits per month.
In a statement, Mr Hanson said giving people access to more information about crime should improve their confidence in policing.
He said: "We know the public want this information, which will allow them to hold the police to account and help create an even more responsive and effective service."
