Colgate, in a statement on Monday, said it had alerted Venezuelan health authorities to the potential risk of the "commercialization and use of these falsified products," without giving further details.

The Venezuelan National Hygiene Institute said it had determined that some toothpastes claiming to be from Colgate did not contain fluoride. Their use posed a health risk because of possible microbiological contamination, the institute said in a public report.

The institute did not mention any reports of health problems but asked Venezuelans to report any that occur.

The fake toothpaste had been imported from China, Mexico and Thailand and had the same color scheme and design as some of Colgate's genuine brands available in Venezuela, the institute said.

Colgate in its Monday statement said buyers could identify the genuine products because the text on the tube and box are in Spanish and show an official sanitary permit.

The institute did not provide details about the number of fake Colgate products in Venezuela or identify the companies producing the toothpaste. Colgate did not respond to Reuters' requests for further comment.

Venezuela's hyperinflationary economic collapse has shuttered most local producers of dental products, stimulating demand for imports of hard-to-find consumer goods like Colgate toothpaste. Many imported goods are sold in black-market stores that do not assess products' quality.

"Several friends have told me to take care, that there are toothpaste brands that damage the gums," Rosa Arias, 61, a maintenance worker, said while shopping at a kiosk in eastern Caracas.

(Additional reporting by Shay Valderrama; Writing by Angus Berwick; Editing by Bill Trott)

By Corina Pons