Thousands of people from Northern Ireland who signed up as extras for the latest series of television blockbuster Game of Thrones have been told to keep quiet about what they see on set.
Filming of the third instalment of HBO's epic show is currently under way here after the runaway success of the first two series which put Northern Ireland on the world stage.
The series will be shot in the Paint Hall film studio and the new sound stages in Belfast.
Various other locations in Northern Ireland will also be used, including the Linen Mill Film Studios in Banbridge.
But TV chiefs are determined to keep details of the much-anticipated third series under wraps until it hits our screens.
Extras NI — based in Belfast — is responsible for recruiting suitable extras for the production.
On Monday morning the agency posted a message on its Facebook page telling members not to share their experiences of working on the show on social network sites, including Twitter.
It read: “Please do not tweet about your time on ‘Game of Thrones’.
“As you know, the producers do their utmost to ensure that plot points are not spoiled for the fans.
“The smallest mention of where you are or what's being shot can be too much information and can be interpreted by the press leading to ‘spoilers’.”
They added: “Additionally, cast, crew and extras should not speak to media or post any photos/comments on blogs or any social networking sites such as Twitter or Facebook.”
In May, it was revealed Game of Thrones is having a striking impact in the modern real world of harsh economics.
It has generated a direct spend in the Northern Ireland economy of £43m, Industry Minister Arlene Foster said.
The £43m is a more than six-fold increase on the original £6.5m injected by Invest NI to secure the original pilot and the first two seasons.
It breaks down into the wages and salaries of the resident cast and crew, hotel bills, the hire of facilities, transport, and the construction costs for shoots in some of the province’s most beautiful locations.
Ms Foster revealed the programme is giving Northern Ireland the biggest worldwide exposure it has ever achieved outside of politics and the Troubles.
“Throughout its lifespan it is likely that Game of Thrones will deliver the widest media exposure Northern Ireland has ever achieved outside of politics and the Troubles,” she said in an Assembly answer.
“Tourism Ireland and the Northern Ireland Tourist Board have, through this drama series, the opportunity to showcase many tourist attractions.”