A number of Hotpoint, Indesit and Creda tumble dryer owners have been warned their appliances may pose a fire risk.
Two types of tumble dryers, condenser and vented dryers, manufactured by Indesit, were sold under the three brands in the UK and other countries over the last 11 years.
The firm is in the process of contacting affected consumers, who were warned not to leave their appliances unattended and to clean fluff from the filter after each use.
In "rare" cases a build-up of lint can come into contact with the dryer's heating element, which could pose a fire risk, the manufacturer explained.
Customers can check online if their appliance is among those affected by keying in the model and serial number on the Indesit website.
A safety warning on the Indesit and Hotpoint websites said: "In some rare cases, excess fluff can come into contact with the heating element and present a risk of fire."
An Indesit spokesman told ITV: "We estimate that a significant number of units will be affected, but at this stage, we cannot speculate regarding the specific figure.
"These products were marketed in the UK and a number of other countries over the past 11 years, so we would expect a fairly large number of them to be affected."
The warning came after an investigation by Whirlpool into dryers sold by Hotpoint and Indesit between April 2004 and September 2015. The US appliance giant acquired the Italian firm last year.