The celebrity panel tries to help Lee and John from Sheffield tell the difference between good and bad mystery singers - without hearing them sing. The last remaining mystery singer will perform a duet with Danny Jones.
Sisters Jen and Nadine from London hope to use their detective skills to spot the impostors and win £10,000. But with a line-up including a singing plumber, a cruise ship star and nail technician, it may be harder than they think.
Father and son Shash and Saaj from Crawley are faced by a line-up of mystery singers including a singing boxer, an actor and a doctor. The celebrity investigators help them choose who should duet with Ronan Keating.
This week the celebrity investigators try to help best mates Anton and Duban from London to tell the difference between the divas and the duds. The final mystery singer will perform a duet with Fleur East.
Brother and sister Leanne and Billy from Stamford try to spot the imposters from a group of mystery singers including a singing student and a personal trainer. The last remaining singer, good or bad, duets with Louise Redknapp.
Caitlin and Kristen from Warrington are hoping to use their detective skills to spot the imposters and win £10,000, with help from the celebrity investigators. Heather Small is this week's guest performer.
In the penultimate edition of the first series, brothers Joe and Dan from Middlesbrough hope to spot the impostors among a singing scientist, a prison officer and an electrician. Alexandra Burke is the music star this week.
The first series of the British version of the singing/guessing game concludes with Ricky Wilson joining the celebrity investigators to try to help Team GB Paralympian Sophie and her boyfriend Josh from Sheffield try to spot the imposters.