The actor, who filmed his final scenes as Frank last month, will be reunited with the mystery culprit on Liverpool station Radio City next Thursday (March 29). Fans who don't live in the Merseyside area can listen online.
Lancel is covering for regular host Pete Price between 10pm and midnight.
The interview will see the top secret cast member in question finally speak openly about their character's guilt.
Confirming the news on Twitter today (March 16), Lancel said: "Exclusive !! Next Thursday 10pm to midnight, I'll be guest presenting @PeteCityPrice show on @RadioCity967. Special guest... FRANK'S KILLER!!!"
Coronation Street fans will see Frank's killer unmasked on Monday, March 19 from 7.30pm on ITV1, bringing weeks of theories and speculation to a close.
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