The Federal Bureau of Investigation is probing to see if Uber Technologies Inc had used software to illegally interfere with its competitors, the Wall Street Journal reported on Friday.

The investigation is focusing on an Uber program, internally known as "Hell," that could track drivers working for rival service Lyft Inc, the WSJ said, citing people familiar with the investigation.

Under the program, which was discontinued last year, Uber created fake Lyft customer accounts to seek rides, allowing it to track nearby Lyft drivers and ride prices, the Journal said.

This also allowed Uber to obtain data on drivers who worked with both the car-ride providers and could have allowed it to lure drivers to leave Lyft with cash incentives, WSJ added.

Uber was not immediately available for comment.

The key question for investigators was whether the program comprised of unauthorized access of a computer, the newspaper reported.