The hacking trial has been brought to a standstill after former News of the World royal editor Clive Goodman was taken ill as he was about to enter the witness box for a fifth day.
The 56-year-old had attended the Old Bailey to be cross-examined for a second day by former NotW editor Andy Coulson's defence barrister.
But the trial was adjourned because Goodman was feeling unwell, the judge, Mr Justice Saunders, told the jury.
The court has heard that Goodman, of Addlestone, Surrey, pleaded guilty to phone-hacking in 2006 with private investigator Glenn Mulcaire.
He now faces charges of conspiring to commit misconduct in a public office, which he denies.
Giving evidence earlier this week, he said Coulson, 46, and others at the defunct Sunday newspaper knew about hacking, and that it was going on on an "industrial scale".
Coulson and all the other defendants in the case deny the charges against them.
The trial will resume at noon on Monday when Goodman is expected to continue giving evidence under cross-examination.