Judge Forrester acquitted Thomas Kramer, a property tycoon, and awarded "substantial" defence costs to be paid by the taxpayer. He then asked for a short adjournment to allow time for the CPS to come to court to give an account of what had happened.
Paul Dodgson, for the CPS, said the alleged victim appeared to be under the misapprehension that her statement could be read in court without her giving evidence in person. "We are in a scenario where we are frankly helpless to interfere," he said. It was impossible to enforce a witness summons in the United States.
Mr Dodgson said the woman had told police last week "she is finding it very stressful and would not attend this country".
The judge said he found it "unsatisfactory" that public money should be used to pay defence bills in such a situation, but awarded Mr Kramer his costs - estimated to run into six figures. "I cannot make an order for costs against a witness, as she is not a party to the proceedings."
Judge Forrester added: "It seems to me to be quite unsatisfactory that a complainant can make two statements saying she wishes to go ahead - then leaves the jurisdiction and indicates shortly before the trial is due that she has decided not to proceed."
German-born Mr Kramer, 42, was not in court to hear the judge's remarks and was due to fly to Switzerland yesterday.
Judge Forrester was also critical of an earlier decision by the prosecuting authorities not to be represented in court for Mr Kramer's formal acquittal and the costs application. The court was "entitled to the attendance of the Crown's counsel to explain the situation in open court".
Mr Kramer was arrested and charged on 12 May. The alleged offence was said to have taken place in his pounds 5m Holland Park mansion, where he began living last April. He was granted pounds 500,000 bail in August.
He is divorced from a German publishing heiress, whose family owns the Bunte magazine empire, and is estimated to be worth pounds 375m. He made millions on the international futures markets and has a property portfolio that includes Miami's tallest building, the Portofino, and homes in Miami, Australia and London.
The CPS said that under its guidelines it had informed the court it would not be attending. If a court decided it wanted the case withdrawn in open court, the CPS was happy to comply.Reuse content