Vicky McClure revealed that she knew about the Oasis reunion for a "good month" before everyone else did.
The 42-year-old actress is best known for her roles in Line of Duty and Trigger Point, with the latter's newest series airing on Sunday (October 26).
While on Radio X on Friday (October 24), Vicky admitted that she knew about the Oasis reunion an entire month before it was announced.
She was brought into the action to record a voiceover for the announcement.
Earlier this year, the Gallagher brothers reunited on stage for the first time in 16 years at Cardiff's Principality Stadium. Until then, they hadn't performed together since V Festival in 2009, which led to a backstage fight at a gig in Paris and the band's split.
The tour was announced last August which caused a mass frenzy with fans desperate to get tickets and spending hundreds just to see the band perform.
Almost 80,000 fans arrived at the venue during each night at Heaton Park, with fans queuing for hours in advance before the doors opened at 3pm.
When mentioned that Vicky must have known before the majority of people that the brothers were set to reunite, she responded: "Yeah. Like by a good month I'd say.
"I mean, keeping secrets, that's definitely up there with the most secret..."
She added: "I'd done a voiceover for Noel for High Flying Birds' Council Skies, and then the same team called me up and says, 'Oh, we're just, you know, wondering if you'd want to do another voiceover.'
"And I was like, 'Yeah, sure! What is it?' And then they were really like, 'Can't really tell you...'
"I was like, 'Am I right?' You know when you go, 'I don't want to say it out loud?' And then yeah, NDAs were signed and off I went, and it was a real honour."
When asked about another series of Line of Duty, the actress teased: "Everybody knows that we would love to do it again. And yeah, I'm pushing for a travel show at the minute with me and Martin (Comptson), just to, you know... Yeah. Because we love working together."