Line of Duty star Vicky McClure left panicking after her co-guest threatens to ...

The final episode is set to air this Sunday, with show watchers desperate to know who the mysterious super villain 'H' is.

Yet Vicky McClure was left panicking on Thursday after her co-guest threatened to reveal a massive Line of Duty spoiler ahead of the finale during an interview on BBC Radio 5 Live.

The This Is England star, 35, appeared on the show to talk about her BBC One documentary My Dementia Choir and she was joined by choir member, Chris, who has become a good friend since the programme.

Scroll down for video  

Panic!: Vicky McClure was left panicking on Thursday after her co-guest threatened to reveal a massive Line of Duty spoiler ahead of the finale during an interview on BBC Radio 5 Live

Panic!: Vicky McClure was left panicking on Thursday after her co-guest threatened to reveal a massive Line of Duty spoiler ahead of the finale during an interview on BBC Radio 5 Live

However, their new-found friendship was nearly in jeopardy after radio host, Nihal Arthanayake, grilled Vicky about Line of Duty and who super villain 'H' really is. 

During the interview, Chris suddenly dropped the bombshell: 'Vicky has told me what happens to H!' 

To which Vicky was left panicking as she quickly squealed: 'Oh my God, Chris! What? Right, we're off air, bye! This is definitely my last interview!'

Regaining her composure and laughing, she added: 'If I get through this... my God, if I get through this, wow!'

Character: The This Is England star, 35, appeared on the show to talk about her BBC One documentary My Dementia Choir (pictured as her character Kate Fleming)

Character: The This Is England star, 35, appeared on the show to talk about her BBC One documentary My Dementia Choir (pictured as her character Kate Fleming) 

Bombshell!: Vicky was joined by choir member, Chris, who has become a good friend since the programme, who suddenly dropped the bombshell: 'Vicky has told me what happens to H!'

Bombshell!: Vicky was joined by choir member, Chris, who has become a good friend since the programme, who suddenly dropped the bombshell: 'Vicky has told me what happens to H!'

However, Nihal, didn't let the moment drop as he asked: 'You're not going to tell us who H is...'

With a defiant Vicky replying with: 'I'm not even going to say the letter!'

Earlier on during the interview, the actress admitted she loves winding up her fellow co-stars by messaging their WhatsApp group pretending there are last minute filming changes.

She said: 'When Martin was thrown over the banister in one of the series - I didn’t really know the outcome but I really wound him up and he was really scared, texting [writer] Jed [Mercurio].

'Oh my God!': To which Vicky was left panicking as she quickly squealed: 'Oh my God, Chris! What? Right, we're off air, bye! This is definitely my last interview!'

'Oh my God!': To which Vicky was left panicking as she quickly squealed: 'Oh my God, Chris! What? Right,

read more from dailymail.....

Get the latest news delivered to your inbox

Follow us on social media networks

NEXT Kim Kardashian leaves Kanye's Sunday service in 'trust god' sweats with ...