But the Sun newspaper, which set up the 'Dianagate' telephone line, immediately announced plans to get round the ban.
The Independent Committee for the Supervision of Telephone Information Services, the watchdog on premium-rate phone services, said it was 'an unreasonable invasion of privacy' to allow callers to hear the tape of an intimate telephone conversation allegedly between the Princess and her friend James Gilbey.
Soon after the ruling, British Telecom shut down the service. But the Sun said it would publish alternative numbers on which the tape could be heard which would be charged at ordinary rates.
The tactic is designed to evade the committee, which monitors only premium rate numbers. The Sun also said it would be going to the High Court today to fight the ban. More than 100,000 people have already called the hotline set up by the newspaper which invited readers to make up their own minds about the authenticity of the 23-minute tape.
The ICSTIS had received one complaint about the premium- rate service - but that protest was enough for the watchdog to act.
Its ruling said the company running the phone service - a subsidiary of News International, the Sun's proprietor - broke a code of practice forbidding 'any unreasonable invasion of privacy'.
The watchdog said it did not know if the taped voices belonged to the Princess and Mr Gilbey, but it did not matter, as privacy had been invaded regardless of who was speaking. It added: 'Anyone with the merest acquaintance with the situation of the tape would instinctively infer the conversation was intended for no other ears than the communicants.'Reuse content