Bingo! Johnius borneensis but close enough, a fresh water croaker called the sharpnose hammer croaker and the way to tell them apart is by dissecting their airbladders, if it is hammershaped and the fish is from the Phillipines it is the borneensis, if it is from farther west and has a sock shaped air bladder it is the carouna. It is bit hard to tell from a picture, eh? there are a few differences like one more dorsal spine, a slight shape variance of the mouth and gill cover and the borneensis has a first anal spine that is much more lightly formed than the others.
Post one up Mahseer.