A cosmetic surgery group is to introduce a loyalty card scheme under which regular customers are rewarded with free treatments.

Non-surgical cosmetic procedures including Botox anti-wrinkle injections and lip enhancements, up to the value of £300, are being offered free to customers after they have paid for four similar treatments.

The card is being offered by the Harley Medical Group.

Group chairman Mel Braham said: "The non-surgical treatments are an important part of our business, indeed for the market as a whole, and we felt compelled to thank the loyal customer base we have had for over 20 years by treating them to a surprise."

The group said demand for Botox had risen at a rate of 2,000% in the past five years. Other treatments on offer free to loyal clients are collagen to smooth out lines and wrinkles, costing upwards of £185, and Restylane, from £255, which is used to treat deeper facial wrinkles.

The same group of clinics previously caused controversy when it offered cosmetic surgery gift tokens.

A spokesman for the consumer magazine Health Which? said: "It is essential that anyone contemplating this type of procedure does their homework and ensures that they are provided with clear and accurate information on the potential risks.

"A surgeon's qualifications need to be checked with the appropriate authorities and their experience in the field of cosmetic surgery verified."