Clients of JPMorgan Chase & Co (JPM) could be excused for feeling dizzy in the last few days after reading the banking group's investment research on Apple Inc (AAPL).

Kevin Chang, an analyst covering telecom equipment for JPMorgan in Taiwan, issued a report on July 8 saying Apple may introduce a phone in the fourth quarter that is inspired by the design of its ultra-slim nano music players and is half as expensive as its $600 iPhone, launched on June 29.

But a day later, Bill Shope, a U.S. analyst who covers Apple for JPMorgan, followed with a note to clients that contradicted virtually everything his colleague had said and questioned the sources Chang used for his take on Apple product plans.

Rather than bring out a low-end version of the iPhone any time soon, Shope said, Apple would likely make its next phone a more sophisticated device with high-speed cellular Internet connections, a feature missing from the current iPhone.

Asked about the conflicting reports, Brian Marchiony, a U.S. spokesman for JPMorgan, said Shope "holds JPMorgan's official view of Apple's stock."

Chang declined comment.

On Tuesday, Apple shares rose as much as 3.2 percent following the report. The stock closed 0.03 percent higher at US$132.39 on Wednesday, underperforming the U.S. Dow Jones index's 0.56 percent rise.

While Shope said the eventual introduction of a cheaper iPhone is "inevitable," he described the prospects for a near-term launch as "unusual and highly risky." He also dismissed Chang's assertion that Apple could convert its nanos to phones.

"We struggle to understand why Apple would abandon one of its most successful product lines with a carrier-centric low-end phone," Shope said.

He also questioned his colleague's sourcing, saying "the majority of Mr. Chang's assumptions on the form factor and functionality of the 'nano phone"' were derived from a patent filing that gave little information on actual products.

Shope said he was unable to independently confirm Chang's reference to unnamed "channel checks" even as he said the channel checks -- supply-chain sources -- were "very interesting and worth further monitoring."

Another investment bank, Goldman Sachs, weighed in on the debate by saying on Wednesday that it was unlikely a nano iPhone was in the works at Apple. Even if there was one, the product is more likely to be launched next year or the year after.