6Consulting has been hired for a project, expected to last six to 12 months, to oversee social media monitoring for the Met.
Although the Met and 6Consulting refused to comment any further, other than to confirm the appointment, it is understood the brief includes monitoring of Twitter, Facebook and blogs.
This activity is being undertaken in order to gain an understanding of how the Met is perceived, but also as an additional way for the police to uncover crime.
One insider said: 'What the Met is looking for is a combination of crisis alerts and management.
'If someone blogs saying "there's a little bit of a riot going on down the street from me", it will be able to respond that bit faster.'
The agency was appointed after a competitive pitch process and reports to Met Police head of internal communication Jim O'Donnell.
6Consulting provides clients with access to social media monitoring software that can be imported into the client's own system.
It is understood that this is what the Met liked about the offering from the agency, which plans to use the software at New Scotland Yard.
Brando director of social media David Cushman said the move was a 'wise first step' in giving the Met a taste of conversations going on about it in social media.
But he added: 'How it responds to what it hears is where the bigger win lies. Joining in makes all the difference.
'That's how the Met can develop an understanding of the role of community policing within online communities.
'Social media offers the Met an opportunity to make itself more accessible, more positively perceived - and more the everyday useful and helpful part of our lives that it should be.'
The move comes after the Met was hit by a storm of negative online publicity following the death of Ian Tomlinson at the G20 protests on 1 April - including two officers caught making controversial comments on Facebook.
But in May, the Met's director of public affairs and corporate comms Dick Fedorcio rejected advice in PRWeek from social media experts to interact with bloggers, saying it 'starts to raise some ethical issues'.
How I see it
Ged Carroll, Director, digital strategies, Ruder Finn
It's an interesting start. Others, such as Merseyside Police, extend this a lot further and engage in active conversation with at-risk groups. For example, an officer engages with the LGBT community through a Facebook group.
It's not only about finding out about crimes, but also doing community policing in a remote way. The risk to the Met is that something could go wrong - it can't cover up its badge numbers online. It's a tough decision, but there's more that can be done.
My community is my friends from all over the place, rather than my neighbours, so going online might make sense.