B777-200 Captain discovered Maintenance had provided incorrect information regarding the history of an ACMP failure mode. Because the Maintenance records contradicted the oral briefing provided by Maintenance personnel; Reporter believes the prevarication to have been deliberate.

Narrative

This report is about aircraft X specifically. In January; I dumped 80;000 LBS of fuel and returned to ZZZ1 due to a Hydraulic Status Message that had generated the following EG Note prior to our flight: 'Boeing is concerned about a recent failure (flash fire) of the right-hand ACMP on this aircraft.' I was assured that everything was fixed and that the aircraft had been flying around for almost a month with no complaints. 30 minutes into our flight (Status Messages are inhibited for 30 minutes after liftoff) we got the Status Message and then returned to ZZZ. Last night I decided to look at the Maintenance history of aircraft X to see -- what was the original cause of the problem? Instead of finding problem; I saw that the aircraft has had the same problem ever since my return to the field. The same problem was deferred in ZZZ2 due to time constraints. This is a fire hazard and the operation of this aircraft should be stopped immediately until the real problem is found. I called the Flight Manager last night to report this.