Coronation Street's Robert Preston will be diagnosed with testicular cancer.

Tristan Gemmill as Robert Preston

Tristan Gemmill as Robert Preston

The bistro manager - portrayed by Tristan Gemmill - is currently behind bars for attacking his old friend Richard 'Rich' Collis (Fraser Ayres), but things are set to go from bad to worse for the hunk this autumn as he will get a shocking diagnosis.

A source told The Sun newspaper: "This is going to be a big storyline for Robert which is likely to have 'Coronation Street' fans hooked for weeks."

The forthcoming scenes will see Robert's girlfriend Michelle McDonald (Kym Marsh) encourage him to undergo life-saving surgery by having his testicle removed but, although she thinks she's supporting him, the testing time may drive them apart.

The soap insider explained to the publication: "It will really test his relationship with Michelle as she tries to offer him support in his darkest hour. But the big question is whether he's willing to accept her help and save himself."

The couple - who got together after Michelle found out her husband Steve McDonald (Simon Gregson) had fathered a child by someone else - have been struck blow after blow this year as the barmaid was being stalked by her ex-boyfriend Will Chatterton ( Leon Ockenden), who is now in prison for his crime, after his return to the cobbles.

Michelle was also forced to give birth to a stillborn earlier this year but, despite the tear-jerking storylines she's been dished out, Kym - who has been on the show 10 years -

thinks her last 12 months on 'Coronation Street' have been the "best" she's ever had.

She said recently: "It's been great. I've been giving some great opportunities.

"This is my best twelve months on 'Coronation Street'. Michelle has no clue (of who her stalker is). He's now dating Maria. Imagine how shocked she's going to be."