A senior engineer at Apple raised concerns that the design of the iPhone 4's antenna could lead to signal problems long before the product went on sale to the public, reports indicate.

Bloomberg has reported that last year antenna expert Ruben Caballero told the firm's management that the device may have faults. Apple has refused to comment on this claim but it appears Mr Caballero's warnings went unheeded.

Apple launched the latest version of the phone last month to great fanfare as it boasted of a design that put the antenna in a stainless steel band around the phone's frame. But it has been plagued with user complaints about dropped calls when the phone is held in a way that covers part of the antenna.

The company has announced that a special press conference will be held on Friday to address the problems customers are experiencing. However, an Apple spokesman declined to give further details, including whether the conference will address the new model's reception problems.

"Given the intense pressure and scrutiny Apple has come under on the problem with the iPhone 4, it's going to be about some kind of fix or compensation for the owners of the phone," said Ed Snyder, an analyst with Charter Equity Research.

Antenna-design experts have said that the phone design, while cutting-edge, was risky because it exposes the antenna to touch. 

What started out as a small number of users complaining about reception has now ballooned into a full-scale public-relations issue.

Critics say Apple has created a public relations headache for itself by appearing to dismiss or ignore the problem, allowing a minor issue to be turned into headline news.

Read more at SkyNews.com.