The consumer group Which? says 400,000 people undergo this type of non-surgical cosmetic procedure in this country each year, and the figure is rising rapidly.

Yet while the US has a strict system of approval and monitoring for treatments, the British government has been dragging its feet.

Consultant dermatologist Dr Nick Lowe, who has clinics in Britain and the US, warned: "Fillers are released in Europe without sufficient scrutiny, information and education on the best way to deliver them."

He estimates that around 65 different fillers containing hyaluronic acid, which is found naturally in skin, are available in Europe compared with only seven approved in the US There, the Food and Drug Administration is responsible for policing new cosmetic techniques, such as the use of dermal fillers.

Its strict assessment regime involves clinical trials to assess both safety and effectiveness.

This has halted or delayed the use of fillers that are widely used in this country.

In Britain, the job of policing fillers is a grey area because it is not clear whether these techniques should be considered beauty treatments or medical procedures.

In theory, the task has been handed to the Medicines and Healthcare products Regulatory Agency.

However, a spokesman admitted: "The regulatory status of dermal fillers is currently undetermined."

The agency has suggested the European Commission is responsible and has produced a working paper which member states, including Britain, are currently discussing.

The drawn-out process means there is unlikely to be any meaningful policing regime in Britain and the rest of Europe for several years.

Which? health expert Frances Burden said: "The Government must tackle this swiftly.

"It has failed to regulate who can administer fillers, despite advice from its own experts, and is leaving consumers vulnerable to products of dubious safety and efficacy."

The problem has been highlighted by the controversy around the dermal filler Isolagen, which was launched in the UK four years ago amid a marketing blitz featuring Dynasty actress Emma Samms.

The treatment, described as a non-surgical facelift, was offered in clinics across the country. The technique, which cost up to £4,500, involved injecting collagen cells grown from patients' skin into their wrinkle lines.

However, hundreds of women are considering legal action because they say it did not work. The company shut its UK operations in March this year.