Mind-blowing Line of Duty theory suggests H’s identity was given away in anagram code earlier this season

‘My head just exploded,’ wrote one viewer

Some Line of Duty fans think they’ve cracked the long-running mystery of the identity of “H”.

The possible answer has arrived in a suitably outlandish fashion, with clues deviously hidden in an anagram.

Spoilers follow for the first five episodes of Line of Duty’s sixth series...

In episode four of the current series, viewers had seen the imprisoned OCG lawyer Jimmy Lakewell (Patrick Baladi) talk to DS Steve Arnott (Martin Compston), who was attempting to get him to turn informant.

At the centre of the speculation is a line which viewers think they heard Lakewell utter to Arnott: “Look beyond the race claim to find H.”

As many fans have subsequently pointed out on social media, “race claim” is almost an anagram for “Carmichael”, minus one letter: H.

Coincidence or not, episode five, which aired last Sunday (18 April), saw the return of the supercilious Detective Chief Superintendent Patricia Carmichael, played by Anna Maxwell Martin.

Many are convinced that the line proves that Carmichael is in fact the traitorous OCG mastermind known variously as “H” and, more recently, “the fourth man”.

Patricia Carmichael (Anna Maxwell Martin) makes a return to the series in this week’s instalment (BBC/World Productions)

“My head just exploded,” wrote one Twitter user in response to the finding.

“Carmichael is definitely bent,” wrote someone else.

However, others suggested that the theory was a little “farfetched”, rightly questioning why Lakewell would choose to tip off Arnott in such an impenetrably cryptic manner.

Other viewers, meanwhile, are convinced that the true identity of “H” is none other than superintendent Ted Hastings (Adrian Dunbar).

Dunbar added fuel to the rumours by delivering a couple of cryptic comments during an appearance on a morning talk show this week.

You can read a full recap of the biggest talking points fromLine of Duty’s latest episode here, including the revelation that Davidson’s mystery blood relative is none other than Tommy Hunter.

Line of Duty continues at 9pm on Sunday on BBC One.