Detectives are investigating allegations of fraud against a London agency that sold tickets for premier events such as Wimbledon.

The investigation comes after complaints by customers who paid inflated prices for sporting and concert tickets which were never received.

Police are looking into two complaints against the agency, the London Box Office Company Ltd, which has now vacated its small ground-floor office at 29 Floral Street, Covent Garden. They would also like to hear from other people who might have experienced problems with the firm.

One of the victims was an American law firm based in the City. It paid pounds 2,200 in February for four Wimbledon women's singles semi-final tickets, but never received them.

The other was a 20-year-old woman from Aberdeen who paid pounds 90 in April for two tickets to see Take That in concert at Wembley in October. All of the tickets were paid for by cheque.

Scotland Yard yesterday confirmed it was investigating the company, saying: 'We are investigating allegations of fraud involving London Box Office Company Ltd of 29 Floral Street. It is alleged that members of the public paid for tickets for a pop concert and a sporting event but received no tickets. The office is now vacated and inquiries are in hand to trace the former occupants.'

The detective said: 'It could be a genuine business that has gone under for genuine reasons meaning that people have been left high and dry.'

Detective Sergeant David Williams, of Charing Cross CID, who is investigating the matter, said yesterday: 'One company paid pounds 2,200 for four debenture seats for this year's Wimbledon ladies' semi-final and they got nothing in return.

'Much the same happened to a girl from Aberdeen who was coming down with a friend for Take That's London show in October.'

The detective said the registered company had operated from the premises for about a year and had left owing pounds 2,000 in rent. Customers contacting the firm had spoken to a Mr Thompson, he said.

'The customers kept ringing to find out what had happened to their tickets, but were told don't worry your tickets will be there. Then the phone was cut off. When I went along I found the office had been stripped - cleaned out.' He said: 'We would like to find out where the company advertised because when people complain they often complain via this route.'

Susan Whiddington, of the Society of West End Theatres, which will write to agents re-iterating any problems and forwards complaints to the police and the Department of Trade and Industry, said the organisation took complaints from the public every day about unscrupulous ticket agents.

She said: 'It is a familiar story. We get complaints from theatregoers, but they are only the tip of the iceberg.' She said that during the peak summer season complaints could run at as many as six a day.

New regulations proposed by the DTI will help to keep rogue ticket agents in check. But that will offer little comfort to victims of fraud who find an agent has disappeared.

Under the proposals, agents and touts selling seats for theatres, concerts and sports events must tell customers what mark-up they are paying, where seats are located and whether the view is restricted.

In face-to-face transactions, they will also have to show customers the tickets or give written details.