Line Of Duty is *the* show everyone is talking about right now, and with the final episode just around the corner, anticipation for answers to the case is currently at fever pitch. 

Everyone has their own theories – many of which we’ve already explored – but what do people with genuine police experience make of Operation Pear Tree? Have they got their own proof of who H is?

Ahead of Sunday’s finale, we spoke with serving and former police officers to see if they’ve cracked the case, and this is what we uncovered… 

‘Fleming is H’

PC Liam Roberts – Metropolitan Police Service

First things first; Hastings is not H. I will always champion Superintendent Hastings (and his luscious locks). He is clearly being set up. 

I allege that DI Kate Fleming is H. A criminal who infiltrates the Police and then applies for a job in Anti Corruption, going up the slippery ladder in order to investigate bent coppers then use them for her own gain.

There’s a look in her eyes that I don’t trust – there’s a coldness. She is a rat and I believe it will be DS Arnott that flushes her out.

I’m also still expecting some sort of twist where Lisa McQueen is involved. If she was a hardened criminal in the OCG, why did she shed a tear when Corbett was killed?

‘Someone high up in the local authority is the one in control’

Ex-PC Janine Pipe – Wiltshire Constabulary 

I don’t think the so-called head of the OCG is police. There is obviously a whole plethora of officers involved but I think the answers lie in social services.

Way back in series one, when Ryan Pilkington was interviewed after his arrest for the gang’s attack on DS Arnott, his social worker was called Jane Hargreaves. We now know for certain that DCS Lester Hargreaves was bent, but I believe he was helping the OCG for a lot longer than his recent brothel visits and that he was related to Jane – possibly his spouse, but more likely siblings.

Working for social services means Jane would have perfect means and opportunity to have had contact with Lisa McQueen, who we know was in the care system. She has also groomed Ryan Pilkington throughout. Someone, high up in the Local Authority is the one in control.

Hastings has been framed as H by ex-DCI Moffatt and Gill Biggeloe, who are both in cahoots with the OCG. 

In fact, I don’t think the so-called H exists at all. The concept originated from DI Fleming’s interpretation of DI Cottan’s dying declaration. He had been completely duplicitous up until then, so why would he suddenly choose that very last moment to assist? He was bleeding to death and as the blood left his body it would impact on his brain capacity – did he even understand?

She also seemed very keen for it to be H, and I think she is complicit in it all. She is trained in undercover operations, confident in a double-role and also has a second mobile. Was it just Fleming’s calls to Richard Akers that DI Denton was referring to when she stated Fleming had an interesting call history back in series two?

‘Hastings IS H, but he’s not bent’

Former Superintendent Ron Winch – West Midlands Police, now Senior Teaching Fellow, Policing at Birmingham City University

H is Hastings but he’s being framed and he’s not corrupt. The question is by whom? It has to be someone very close to the investigation and aware of Ted’s vulnerabilities – that means either Kate Fleming or Steve Arnott. 

I believe we will see Hastings exonerated, leaving egg on the face of DCS Patricia Carmichael. She’s a great character and I think she will reappear as Hasting’s boss and the new ACC in the next series.

I expect Kate to be identified as framing Hastings as ‘H’ and she will be killed off in the finale. There is a lot of chatter about Steve Arnott having been offered the next series, and to my mind that rules him out. 

I suspect that the other big reveal will be that Lisa McQueen is an undercover cop who will then appear as the new DI with AC-12 for the next series, in place of Fleming. 

‘H isn’t a surname, but a position of a high ranking officer’

PC Natalie Perrett – Avon and Somerset Constabulary 

I think H is the DCC, Andrea Wise. I don’t think ‘H’ stand for a name, I think it means ‘head’, and she’s one of the the highest ranking officers. She’s the one who made the decision to pull AC-12 off Operation Pear Tree, and she seems very cagey. She might not have a main part but she’s the one with a hold over everything, and can control different officers and who can see what. 

McQueen is also either an UCO for a different department, or she’s the daughter of Tony Gates and Jackie Laverty. She’s definitely got some ulterior motive to being part of the OCG – either she’s trying to get back at them for killing Jackie, or she’s a UCO and didn’t know Corbett was one too, but had to carry on because she was so deep in it. 

There was mention as well that Corbett potentially could be Hastings’ son, because of the northern Ireland connection. It could be that Ted had an affair with Corbett’s birth mum, hence why he’s taken a vendetta against him and his wife.  

Will any of their theories prove to be correct? Find out when Line Of Duty concludes on Sunday at 9pm on BBC One with an extended 90 minute episode.