Payment made to a informant or grass by the pigs.
I reckon he's on the blue giro after the police let him off.
av radixx 20 november 2010
An informer, on the police's payroll. Derived from the fact that payment comes in the form of a giro cheque, and that the police in England are sometimes called 'the blues'.
Yo chill out man, did you hear about Bobby? He's an informer, he's a blue giro man, chill out yeah!
av Facey_Moh 25 september 2010