Dozens of illicit mobile phones have reportedly been discovered inside prisons after the Government's emergency wildfire alert caused hidden devices to sound simultaneously in inmates cells. The nationwide warning was sent to phones across England and Wales on Friday amid a very high wildfire risk, producing a loud siren even on some devices set to silent. The unexpected alert exposed contraband phones being secretly used by prisoners, allowing officers to identify devices from the sound and providing security teams with intelligence about where others were being kept. Illicit phones were reportedly recovered at prisons including HMP Belmarsh in south London, HMP Feltham in west London and HMP Frankland in County Durham. A prison source said that some security teams had anticipated the opportunity and instructed officers to listen for phones when the alert was transmitted, while staff elsewhere reacted after hearing devices sounding inside cells. Officers subsequently searched cells and other areas where alerts had been heard, according to the report. The source suggested the operation could ultimately have exposed hundreds of illicit phones across the prison estate, although no official nationwide figure has been released. Mobile phones are prohibited for prisoners because they can be used to communicate outside authorised channels and facilitate criminal activity. Contraband devices can consequently command prices reportedly reaching thousands of pounds inside prisons. The unintended security benefit came after the Government used its emergency alert system to warn residents, landowners and visitors across England and Wales to avoid activities capable of starting fires amid exceptionally high wildfire risk. (FILE PHOTO) #UKPrisons #Wildfires #EmergencyAlert