Apple's iPhone is the world's hottest smartphone _ and one iPhone in Australia appears to be the hottest of the bunch as it spontaneously began smoking last week.

Regional Australian airline Regional Express described the "mobile phone self combustion" in a statement. It said that an iPhone belonging to a passenger began to expel a "significant amount of dense smoke" and give off a red glow after a flight from Lismore, Australia, landed in Sydney on Friday.

A photo accompanying the statement showed the shattered, warped back of a recent-model black iPhone.

The airline said a flight attendant extinguished the glow and nobody on the plane was hurt. Regional Express reported the incident to the Australian Transport Safety Bureau and the country's Civil Aviation Safety Authority, and gave the phone to the bureau so it could be analyzed.

"We look forward to working with the officials investigating this incident," Natalie Harrison, a spokeswoman for Cupertino-based Apple Inc., said Tuesday.

There have been occasional reports of extreme gadget overheating in the past, often in relation to rechargeable lithium-ion batteries. The batteries have been the subject of several recalls of consumer electronics: Millions of laptop batteries made by Sony Corp. for Apple Inc., Dell Inc., Lenovo Group Ltd. and other PC makers were recalled in 2006 and 2007 after it was discovered that they could overheat and ignite.

Earlier this month, Apple recalled first-generation iPod Nanos sold from late 2005 to 2006, citing faulty batteries from one supplier that in rare instances could cause the device to overheat.