Sarah Parish says 'Broadchurch' scripts are given "code names" to maintain secrecy.

Sarah Parish

Sarah Parish

The 48-year-old actress - known for appearing in BBC sci-fi drama 'Doctor Who' and Sky 1 comedy series 'Trollied' - will join the popular ITV crime drama for its final series later this month, and has said the need to keep plot details under wraps was so intense there was even security placed on the scripts.

She told the Daily Mirror newspaper: "All scripts have a code name and there is a different writer's name. Our names are printed throughout the script and often the top actors have code names too, so people don't come to the set."

It isn't just the cast - which includes David Tennant and Olivia Coleman returning as Detective Inspector Alec Hardy and Detective Sergeant Ellie Miller respectively - that have to work on keeping plot details a secret, as producer Dan Winch admitted he's often "paranoid" about leaving hard copies of scripts lying around.

He said: "We send out scripts on email and everyone has a unique password. I'm so paranoid I will leave my hard copy script around I shred them after script meetings so I just have them on digital.

"Everything is watermarked and the sides each day have your name on them, but we have had some near misses where people have left them lying around by accident."

And Dan revealed one occasion where they were forced to take the extreme measure of shutting down an email account for fear of scripts being discovered.

He added: "We had someone who went on holiday and their laptop got stolen somewhere in Europe and we had to shut down and change the email addresses for that person.

"We take everything really seriously and for the right reasons to make sure for that launch we won't have given away anything that will ruin the journey.

"All the scenes that have involved quite dark, quite sensitive emotional content, it wouldn't be appropriate for those pages to be flying around at the farm shop we have been at on various occasions, so we are just careful and make sure we do everything we can possibly do to maintain that secrecy and suspense."

'Broadchurch' will return to ITV at 9pm on February 27.