Local authorities are paying increased attention to the practice of spirit substitution or "tipping" in hotel and restaurant bars, warns the International Federation of Spirit Producers (IFSP).

Tipping occurs when cheaper own-label or bootlegged spirits are poured into branded bottles and consumers are charged the higher price. It can net unscrupulous owners up to £15 in extra profits per bottle.

"Previously, we have targeted pubs and bars," said Philip Scatchard of the IFSP, which provides trading standards and environmental health officers with kits to determine the authenticity of the major spirit brands.

"Now we are turning our attention to other areas of the licensed trade and hotels and restaurants in particular."

An IFSP survey in 1999 using former trading standards officers found that tipping occurred in 8% of pubs and bars and cost the consumer about £30m a year. The rate has since decreased to 4%, and the cost to consumers to £20m-£22m.

While the IFSP has not conducted similar surveys of hotels and restaurants, Scatchard believes the offence rate is similar to that in pubs.

The fraud was most common in proprietor-owned hotels, restaurants and bars, rather than chains and managed pubs, claimed Scatchard. Owners were the usual culprits, but Scatchard added that tipping sometimes occurred when staff tried to cover their tracks after a private party or transgressions when the owner was away.

Despite the illegal profits, Scatchard warned that tipping could prove "a high-risk crime" with penalties of up to £20,000. And because local licensing officials are informed of any spirit fraud prosecutions, offenders risk losing their licence if any further problems occur.

In March, the owner and two joint licensees of the Peking Inn restaurant in Aylesbury, Buckinghamshire, were ordered to pay two fines of £1,000 and one of £800 (plus £691.20 in costs) for selling vodka and whisky falsely advertised as Smirnoff and Teachers Highland Cream.