Bancroft, ITV review - Sarah Parish's very cold case

This week we were all meant to be gripped by a bunch of ancient geezers nicking diamonds in Hatton Gardens. The postponement of ITV’s nightly four-part drama – the second of four (four!!) different versions of the infamous burglary – is a bit of a mystery. Now you see it on the cover of the Radio Times.

What does it say about a drama that was to have been launched in a graveyard where thousands not millions of viewers await? After two episodes viewers were reporting to DCI Twitter that it’s a rip-off of Line of Duty 4. The overlap is more than superficial: a senior female detective is involved in covering up a murder she herself committed, while privately trashing DNA evidence that incriminates her.

But the differences are legion. Where Line of Duty makes a point of being determinedly pernickety about form-filling procedure, Bancroft has carefully selected the bonkers route to crime drama. Detective Superintendent Elizabeth Bancroft (Sarah Parish) stabbed the pregnant wife of her lover 27 years earlier, when she was a young WPC who just happened to be the first at the crime scene when it was reported. Now similarly young detective Katherine Stevens (Faye Marsay, pictured right) is working on a cold case that has been sent her way by another senior policeman (Adrian Edmondson), who just happens to be a rival for the vacancy when Art Malik’s top copper retires. “Bancroft,” he counselled murkily, “doesn’t help anyone but Bancroft.”

So far Bancroft has murdered an old colleague in a wheelchair then given the eulogy at his funeral, blown up the flat of the sister-in-law of Latif the druglord after placing her and her child in witness protection, offered to collude with Latif’s brother Daanish (Ryan McKen) and turn a blind eye to his future criminal activities if he gives evidence about gun-running, and had sex with her old flame Tim (Linus Roache, pictured below) in order to frame him as the killer of his own wife.

This absolute fridge has somehow kept all her psychological flaws under wraps for a quarter of a century. Having previously pimped her son to Stevens (“Why don’t you give a nice boy a chance for once?”) for her own ends, the penultimate episode closed with Bancroft threatening her with all manner of direness if she so much as breathed a word about her being a murderess and all that. Meanwhile Anya Kirim (Amara Kara), the forensics specialist with whom Stevens is working on the cold case, just happens to be best mates with the woman in witness protection, so chose to play down her suspicions of Bancroft until such time as she’d nailed the druglord.

Viewers have noticed that Parish’s scar goes walkabout on her face, while Linus Roache’s hair stylist picked the wrong shade from the colour swatch. It all feels a bit phoned in, which may explain why Bancroft’s scenes keep getting interrupted by the trill of her mobile. “I need to get this,” she says. Enough already? Marsay is good, and Bolton looks nice from the drone cam. The annoying thing is you want to see it through to the end.

• More TV reviews on theartsdesk

@JasperRees