Line of Duty series 6: Fans spot sinister detail hidden in Jo Davidson’s blood relative reveal

*Warning: This article contains spoilers for Line of Duty*

Line of Duty delivered one of the biggest cliffhangers in its history recently, and it turns out it was even more shocking than we realised.

Millions of viewers let out a collective gasp when Jo Davidson (Kelly Macdonald) was revealed to be the daughter of Tommy Hunter (Brian McCardie) during Sunday’s episode.

Now, fans have done some digging of their own and uncovered another clue that reveals a more sinister side to their relationship.

A post-it note next to Tommy’s portrait on the wall at AC-12 claims that not only is Jo the daughter of Tommy, but ‘both his niece and daughter’.

If you look closely enough, it reads: ‘Jo Davidson’s DNA has been identified at Farida Jatri’s house. A match has been made to Tommy Hunter stating she is both his niece and daughter.’

Any medical expert would also have noticed the term used by Steve Arnott (Martin Compston) when describing the DNA match.

Steve spoke about ‘homozygosity in their DNA’, and the terms suggest the pair are very loosely related and there could even be an incestuous link.

The implication is that Tommy conceived a child with his sister. As Tommy is only 14-years older than Jo, it adds an even more troubling dynamic into the equation too.

It’s caused fans to speculate online about the nature of their relationship and how it could have had an impact of Jo’s route into the police service.

Viewers were stunned after the link between Jo and Tommy was confirmed, with Tommy at the heart of corruption on the drama since series one.

Jo, who is leader of Operation Lighthouse and heads up the search for Gail Vella, has been trying to cut her ties with the Organised Crime Group (OCG) over recent times.

But this connection is bringing her past to the fore as the series heads towards its conclusion.

Meanwhile, fans have been doing their best detective work across the entire series to try and crack the mystery of season six – see all the clues you might have missed here.

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

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