* All retail supplies recalled in U.S. and Puerto Rico
* European sales of Alli unaffected by move
* Company investigations ongoing (Adds background on drug, detail on reported tampering, furtherGSK comment)
By Ben Hirschler
LONDON, March 27 (Reuters) - GlaxoSmithKline isrecalling all supplies of its non-prescription weight-loss drugAlli in the United States and Puerto Rico after customersreported finding other pills and tablets in some bottles.
The news is a fresh blow for a product once touted as apotential blockbuster but which has had disappointing sales overthe years - aggravated, in part, by a separate supply problemtwo years ago.
The British group said it believed that some U.S. bottles ofAlli might not contain authentic product, adding that it wasworking with the U.S. Food and Drug Administration on theretailer-level recall.
News that bottles had been tampered with first emerged onWednesday.
GSK has received inquiries from consumers in Alabama,Florida, Louisiana, Mississippi, New York, North Carolina andTexas about 20 bottles containing tablets and capsules that werenot Alli.
The treatment is also sold in Europe but the company said noproblems had been detected there and European sales were notaffected by the U.S. recall.
GSK said it was not immediately clear how the bottles hadbeen tampered with or where in the supply chain the problem hadoccurred.
NO THEORIES YET
"The investigation is ongoing. We've asked people to returnbottles to us, so we can examine them very closely ... we don'thave any theories at this point," a company spokeswoman said.
Shoppers said they had found a range of tablets and capsulesof various shapes and colours in purchased Alli containers. Theauthentic drug is a turquoise-blue capsule. Some bottles insidethe outer carton were also missing labels and had tamper-evidentseals that were not genuine.
There have been no reports of any serious illnesses relatedto the product after news of the tampering.
Quality problems have become a big issue in thepharmaceuticals industry, with most attention focused on Indiangeneric prescription drug suppliers. However, Western gtoupssuch as Johnson & Johnson have also suffered failures inquality control.
Alli is marketed by GSK's consumer healthcare business andis approved for over-the-counter (OTC) sale for overweightadults, in conjunction with a low-fat diet.
The treatment, which is a low-dose version of Roche's Xenical, was launched in the United States in 2007 witha big marketing campaign. But the product has failed to achievethe $500 million to $1 billion of sales analysts had initiallyforecast.
GSK no longer breaks out Alli sales figures, though revenuefrom the product was 93 million pounds ($154 million) in 2011.
The company tried to sell the Alli brand that year, alongwith a number of other non-core OTC healthcare products, but itsdivestment was scrapped after an interruption in supplies fromRoche, which makes the active ingredient for the drug.($1 = 0.6037 British Pounds) (Editing by David Goodman)