Prisoners are converting to Judaism as part of concerted efforts to receive better quality meals after they were inspired by a Netflix show, a report has claimed.
Inspectors who visited HMP Edinburgh ordered an 'urgent investigation' after almost £1 million was spent serving specially prepared kosher meals to more than 100 prisoners in 2017.
In 2014, only nine inmates at all Scottish jails were registered as Jewish. The Scottish Prison Service (SPS) launched a crackdown after the apparent scam spread to other prisons across the country.
It followed a plotline in a 2015 episode of prison sagaOrange is the New Black where Cindy, played by Adrienne C Moore, converts to Judaism to get "better quality food" and sees her swap out pork for Kosher chicken.
70 of her 200 fellow inmates follow suit in a revolt against the new cheap food being shipped into the prison.
In general, food prepared for special dietary requirements is seen by many inmates as being of a higher standard than the typical prison menu, but the added cost to the service is far higher.
The cost of feeding inmates in Scotland reached a record high of £964,000 in 2017.
As a result, the SPS introduced a stricter registration scheme for those applying to have kosher diets on religious grounds and have since seen a drop in numbers.
The number of inmates claiming kosher meals at HMP Edinburgh has fallen by three quarters and the total cost of feeding inmates at the jail dropped by £80,000 in the last year.
Across the country the total cost of feeding prisoners fell from £6,566,216 to £6,473,701 in the last 12 months - a drop of £92,515.
A Scottish Prison Service spokesman said: "For several years, we had a number of people who claimed to be Jewish and were only able to eat a kosher diet when in all probability they weren't.
"To combat this we introduced a policy which has a more rigorous registration and we have since, across Scotland, had fewer kosher inmates.
"Basically, the system before was that people said they were Jewish so required a kosher diet, and in some places they received it.
"If someone requires a kosher diet they will get it but when we tightened up the requirements and made it slightly more bureaucratic, people suddenly decided they weren't."