DC Chief Says Amber Heard's Role in 'Aquaman 2' Not Affected by Depp

Amber Heard's participation in 'Aquaman 2' -- however minimal it may end up being -- had absolutely nothing to do with Johnny Depp ... so says the guy who heads up DC Films.

Walter Hamada -- WarnerMedia's head honcho for all things DC movies these days -- sat for a deposition that was played in court by Johnny's team Tuesday ... this as a rebuttal witness after AH's squad rested their case, and as closing arguments approach on Friday.

Check out his testimony ... he tells JD's attorney, Ben Chew, that whatever was going on in the outside world between Amber and Johnny these past few years had no bearing on Warner's decision to downplay her role as Mera -- nor did it affect how much they paid her.

As you know ... there's been much speculation and rumors that AH is seriously sidelined in the 'Aquqman' sequel, this after significant screen time in both the OG and 'Justice League.'

Amber's attorneys have trotted out witnesses who've suggested Amber lost not just a big part in the movie, but big money that should've come with it ... in the form of a renegotiation upon the success of its predecessor, which they say is SOP in the movie biz.

WH addressed that head-on -- saying that under his watch, Warner made clear they wanted to reign in all these pay raises -- which can be costly -- and hold people to option agreements in contracts they originally signed with them ... and AH got a taste of that, he says.

She made a mil for the first movie, and since WM exercised her option for the sequel without rejiggering the deal ... they only gave her $2 mil -- something Amber's attorneys have called a blatant sign her career's been damaged by this whole saga.