While Google has made little secret of its efforts to develop its own car, complete with fully autonomous capability, rival tech giant Apple is yet to make its own plans—or lack thereof—known. However, despite Apple’s penchant for secrecy, there are several clues that suggest the Cupertino-based firm is working on autonomous car of its own, one powered by an electric drivetrain.

The latest clue comes from comments made by Apple engineer Frank Fearon to The Guardian. Fearon works for Apple’s secretive Special Projects group and has confirmed to the newspaper that Apple has been in talks with GoMentum Station, a former naval base located near San Francisco that's currently in the process of being converted into the world’s largest secure facility for autonomous and connected car development. Automakers like Mercedes-Benz and Honda already use the site.

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“We would ... like to get an understanding of timing and availability for the space, and how we would need to coordinate around other parties who would be using [it],” Fearon is reported to have said.

Randy Iwasaki, the man in charge of GoMentum Station owner Contra Costa Transportation Authority, has also confirmed to The Guardian that Apple has visited the site and is interested in it.

The GoMentum Station spans more than 5,000 acres and already includes more than 20 miles of paved roads. There is said to be a variety of common road structures including highway overpasses, railway crossings, tunnels and cattle grids. In the video below, you can see an Acura RLX prototype testing some autonomous features at the site.

It was in early 2015 that news of an Apple car first emerged under the alleged code-name of Project Titan, and though the basis of the news was purely speculative at that point there was the fact that Apple had already poached a number of engineers from electric car startup Tesla Motors [NSDQ:TSLA]. Then it emerged that Apple had poached more engineers, including some from electric car battery supplier A123 Systems as well as a former quality control chief from Fiat Chrysler Automobiles [NYSE:FCAU]. And just this month it was reported that Apple CEO Tim Cook and some other senior execs had visited BMW and taken a tour of the facility where the i3 electric city car is built.