Galaxy Note 7 owners are being told to turn off their smartphones amid new safety concerns.

Samsung says it is halting worldwide sales of the model as it investigates further reports of devices catching fire.

The latest warning apparently includes replacements following a big recall last month.

In a statement issued late last night, the phone giant said consumers with either the original devices or those obtained following a recall should turn off the power and either ask for a refund or exchange them for different phones.

It's believed a new product defect had been found in Samsung's most popular smartphone, but it's not known what this defect is.