Billie Piper recently missed two preview performances

The former Doctor Who star failed to appear on stage at the Garrick Theatre for a preview performance ten days ago.

The 25-year-old missed another preview on Tuesday, after collapsing shortly before she was meant to appear.

Signing autographs after the show she said: "I'm very well. I had gastric flu but I'm better now."

Concerns for the former pop star's health started, after she was photographed apparently crying in the street, alongside former husband Chris Evans, who had watched Monday's preview performance.

She recently admitted to finding theatre work tough.

'Stressed out'

"It's really hard in the theatre and the level of concentration is terrible. I'm still working it out and trying to find my feet," she said.

"I'm quite stressed out and I'm having a tough time. I'm still very green," she added.

Piper plays Ann, a young professional at a struggling newspaper.

I think she could have had a meatier role. She's a very accomplished young actress and I think she's got a lot more to do Jill Towner, member of the audience

She is currently dating co-star Laurence Fox, who plays office bore Patrick.

Audience member Jane McKay, from London, said she enjoyed her performance on stage.

"I think she could have had a meatier role. She's a very accomplished young actress and I think she's got a lot more to do," she said.

Jill Towner, from Cambridge, said: "It was a tough one for her first West End performance but I thought she was very good."

Ill-health

Piper is the latest high-profile performer to fall ill while performing in the West End.

The Sound of Music star Connie Fisher will be absent from the hit production for the next fortnight after damaging a vocal chord.

Fisher, who won the part in the BBC talent show, How Do You Solve A Problem Like Maria? has missed several performances over recent months through ill health.