'Doctor Who' Star Discovers His Dad Wasn't His Biological Father on TV Show

'It spun my world,' the actor said.

The British actor John Simm, best known for his roles in the hit shows Doctor Who and Life on Mars, has been left reeling by a real-life plot twist. The 54-year-old thespian recently uncovered a startling truth about his lineage while participating in the British television series DNA Journey.

The genetic exploration program, which aims to unravel the ancestral backgrounds of its celebrity participants, delivered a bombshell to Simm when DNA test results indicated that Ronald Simm, the man he had known and loved as his father throughout his life, was not his biological parent. "It spun my world, and everything I thought I knew, wasn't real," Simm said in a statement to People magazine.

The journey that led to this life-altering discovery began innocuously enough. Simm, born in Yorkshire, had initially joined the show as a gesture of support for his Life on Mars co-star Philip Glenister. "It's turned out to be such a massive thing in my life and all I was doing was a favor for Phil so he didn't have to do it on his own," Simm explained.

As the genetic investigation unfolded, it was revealed that Simm's biological father was a man named Terry Smith, who, like Ronald Simm, had already passed away. In a twist that seems almost scripted, it came to light that Smith had lived in the same vicinity of Manchester as Simm and frequented the very working men's clubs where the actor and his father Ronald had performed during Simm's early musical career, according to the outlet.

"The thing that blows my mind, me and my dad, we played around here loads of times, we definitely played here a lot and he might have been in the same pub one night and watched me play," Simm reflected during the show, via People. The actor, drawing parallels to the science fiction narratives he's familiar with, added, "I can't get it out of my head, because we played this area in the 80s and he was here and he was in working men's clubs. It's one of those mad, 'Back to the Future,' 'Life On Mars' things."

The discovery about his parentage wasn't the only surprise in store for Simm. Prior to the DNA test, a conversation with his mother had already begun to unravel the fabric of his family history. Simm recounted on the show, "When they had me, in the sixties, they were both young…they were together and then they split up and were both with other people and then they got back together and then they had me. I'd never heard this story before."

The emotional journey culminated in a poignant meeting with Karen, a half-sister Simm never knew existed. This encounter provided him with an opportunity to learn about his biological father through shared memories and visual mementos.

For Simm, whose career has spanned iconic roles in British television, including the recent ITV drama adaptation of Irvine Welsh's Crime, this personal discovery has added an unexpected chapter to his life story. The actor, who had previously spoken about his grief following Ronald Simm's death in 2015, now faces the challenge of integrating this new knowledge into his sense of self and family.

In a previous interview about his father's passing, Simm had said, per Daily Mail, "When someone dies, you're left with this huge black hole in your life. People say, 'You'll get over it,' but I don't want to get over it. I always want to remember my dad. I've still got his number in my phone. Every so often I see something on TV that I think he'd like and I pick up my phone to text him, still." The episode featuring John Simm's remarkable discovery is set to air in the UK on October 9, promising viewers an intimate look at the actor's story of self-discovery.