Line of Duty star Martin Compston offered new two-series deal ahead of police drama’s season five climax

LINE of Duty star Martin Compston has been offered a new two-series deal to play DS Steve Arnott in the hit cop drama.

Writer Jed Mercurio is desperate to tie down the Scottish actor in order to plan for future series following the climax of series five this weekend.

So far only series six has been confirmed, but the move to sign up Compston for another indicates Mercurio is already penning a follow up.

A source said: “Everything is being kept under lock and key, but behind the scenes bosses are secretly trying to tie down key castmembers.

“Martin is a mainstay of Line of Duty and crucial to future plotlines.

“The offer is on the table and the likelihood is he’ll accept, as he appreciates just how big the series has become.”

The cop drama has attracted incredible ratings so far this series, with last Sunday’s penultimate episode watched by 8.3million people.

Viewers have been left in suspense over the identity of bent copper ‘H’, with AC-12 boss Ted Hastings, played by Adrian Dunbar, currently the bookies favourite, alongside Gill Biggeloe (Polly Walker) and Kate Fleming (Vicky McClure).

Compston, 34, has starred in all five series of the cop drama, which kicked off on BBC2 in 2012.

He’s combined his role as the straight-laced cops with roles on TV dramas Victoria and Silent Witness, while also appearing in Hollywood movie Mary Queen of Scots as Lord Bothwell.

The Scot has also just been cast alongside Cheat actress Molly Windsor in new crime drama, Traces.

The show, which is based in the Scottish Institute of Forensic Science and Anatomy (SIFA) in Dundee, is based on an idea by writer Val McDermid.

The best-selling author also produced the novels which were adapted into the Wire in the Blood crime shows starring Robson Green.

Filming on the the six-parter will start soon and the show is set to air on Alibi later this year.