Jonsson was due to start rehearsals next week

Channel 5 is now looking for a replacement presenter for its high-profile new show Jailbreak, which Jonsson, 33, was due to start work on next week.

She is resting at home with her partner and father of the child, German businessman Markus Kempen.

Jonsson's agent, Melanie Cantor, said: "She is devastated, but resilient."

The presenter - best known for the BBC's Shooting Stars and ITV's Gladiators - already has a five-year-old son, Cameron, from her marriage to cameraman John Turnbull.

Cantor told The Mirror that Jonsson was planning to "take it easy" until the birth.

"Everyone's main concern now is that it is all right," she said.

"She has had a really traumatic few months. Now she has to prepare herself for the hard months following the birth."

Jailbreak has been billed as a reality TV show to rival Channel 4's Big Brother.

To be shown six days a week for three weeks from 12 September, it follows 10 contestants as they battle to escape from a "prison" to win a �100,000 prize. It will also be shown on the internet.