Screenshot by Matt Elliot/CNET

Google Maps might not gain admission to Apple's App Store, a new report claims.

Although Google is hard at work developing a Maps app that will be available in Apple's App Store, the Guardian is reporting today, citing sources, that it might never find its way to that marketplace. After speaking to Google employees, the Guardian found that the search giant is "not optimistic" that Apple will approve Google Maps.

There is certainly no love lost between Apple and Google. Since the inception of iOS, Apple offered a built-in version of Google Maps. However, with the launch of iOS 6 earlier this year, Apple ditched Google's service for its own Maps application, fueling an increasingly bitter battle between the companies. Apple also removed Google's YouTube app from its software.

Interestingly, Apple approved a YouTube app for admission to its App Store. However, Apple doesn't have a direct YouTube competitor, which likely led it to accept the app. Google Maps is still accessible in the iOS browser.

If Apple decided against approving Google Maps on the grounds that it's a competitor, it would call the company's decision to allow a host of other mapping apps, including MapQuest, into question.

Luckily for Apple, it has time to consider its options. According to the Guardian's sources, the dedicated Google Maps application won't be ready until later this year. When it is available, however, Google plans to send the program over to Apple for approval, potentially causing a bloody battle over Apple's balance between self-service and competition.

So, why does Google feel so doubtful of Apple's willingness to approve its app? According to the Guardian, some sources point to a "Find maps for your iPhone" section of Apple's App Store that lists several free and paid alternatives to Apple's widely panned Maps application. None of the listed applications use Google's Maps application programming interface to deliver points-of-interest or routing data, leading one source to suspect that Apple doesn't want to risk promoting Google's services.

That said, there are some sources who told the Guardian that there is still a glimmer of hope that Apple might approve the app. The issue is, they don't believe the approval will happen quickly.

CNET has contacted both Apple and Google for comment on the report. We will update this story when we have more information.