TechCrunch said it has verified with at least three manufacturers that the next iPhone is likely to have a 19-pin "mini" connector that will replace the present 30-pin port.
"Three independent manufacturers all agreed that the 19-pin dock port is in the works and many accessory manufacturers are facing an uneasy few months as they wait for official news of the standard to be announced," it said.
It said the new port is similar in size to the Thunderbolt port available on new MacBook devices although the manufacturers said the pin layout will be different.
Since Apple released its third-generation iPod, the 30-pin ports have been its standard.
But it said that while the 30-pin connectors offered structural stability when connecting to most accessories, the introduction of the MagSafe 2 port showed Apple is "more concerned with space savings inside each device."
Meanwhile, a separate article on MobileFun indicated fresh images may confirm the next iPhone will be a "fairly drastic redesign" from the iPhone 4 and 4S.
It quoted one manufacturer as saying it is already preparing to construct iPhone 5 cases - and ship replacements for free if they turned out to be less than perfect.
MobileFun said there may be at least three big changes from the old iPhone 4S to the iPhone 5, which include:
The phone is much bigger, measuring 58.47 mm wide, 123.83 mm high and 7.6 mm thin. The screen is 4 inches.
The earphone jack has been relocated to the bottom of the phone.
The dock connector is much smaller, similar in size to micro USB.
Other possible changes include much bigger and more pronounced speaker grilles on the bottom of the phone; and a new rear chassis with a two-color aluminium design that separates the main rear cover from the antennae.
Changes inside the phone may include a high-speed LTE connectivity and the iOS 6 operating system.
The phone is expected to launch in October.
