Contraband thrown over Erlestoke Prison fence
Two bags containing Class B drugs, mobile phones, Sim cards, CDs and computer games have been found at HMP Erlestoke Prison near Devizes.
The bags were thrown over the perimeter fence in two separate incidents.
Wiltshire Police said the items would have a "significantly high value" within the prison and have begun an investigation.
A Prison Service spokesman said there was a "zero-tolerance approach to drugs and mobile phones in prisons".
He said: "HMP Erlestoke is a rural prison, and our security measures there are subject to constant review.
"Any banned items found within the prison will be dealt with appropriately and, if necessary, referred to the police."
The spokesman declined to say how often incidents of this nature take place at the prison.
A recent inspection at Erlestoke reported that the availability of illegal drugs among prisoners remained a "serious problem".