Sources with direct knowledge tell TMZ ... ABC's human resources and legal departments are working together to look into all aspects of the high-profile co-workers hooking up. The goal is to determine if Amy and T.J. did anything to breach their contracts -- such as using company resources, like vehicles or drivers, to meet romantically ... or pressuring staffers to keep the relationship on the DL.

We're told some people at the network were upset about ABC News' President Kim Godwin's comments on Monday morning's editorial call -- when she said the couple did not violate company policies -- because the network hadn't yet taken a closer look.

Our sources say the review started to heat up internally last Friday when news broke of an alleged affair T.J. had with a former 'GMA' producer years ago.

We're told Godwin worked through the weekend with other executives before deciding to pull Amy and T.J. from the anchor's desk.

As we reported, Amy and T.J. were taken off the air Monday after Godwin called the situation an "internal and external distraction."

That part is clearly true, but again, other execs feel she went too far in telling the team there were no company policy violations -- we're told it was just too soon to know.