i heard the missing private eye was in the lake

The largest I hv seen was inside the Giant plentong Aquarium shop..I think probably ~1.5 X normal human..Dunno whether the fish still there. This one by Nat Geo:

The fish is not even Asian species...It's native of South America. Chances are, somewan throw it inside the lake as kenot tahan maitaining it...so another guy go fishing & caught it up..well probably not Mines but can be any lakes/rivers in Malaysia

ya also i have seen before at giant plentong The fish really big ...Dont know now the fish still there or not ...

Well, Other than South America's Arapaima, SEA also having the 2nd largest fresh water fish in the world..i.e the Mekong river catfish:

This fish can eat human 1 or not?

Arapaima is fish predator...So far never heard its attack human as u can see the guy swimming inside the big tank...but Long-long time ago, while visiting few nurseries in Bakri Muar Johor and my 1st encountered wth this huge fish, the owners were telling me they might grabbed our hand just like Toman! So I not dare putting my hand inside the tank liao

i heard inside the lake got nessie's cousin

after u whack ppl u send them swimming with the fishes here...

You can see this kind of fish in batu pahat, johor. There is one chinese temple near the sea which rare few of this fish. Quite a lot of people visit there.
And you can use your hand to stroke the fish. They said will bring luck.

giant Arapaima eat small fish, so it might grab ur hand!

I think by now Johor is the state where ppl really crazy of this fish...Even during late 80's, I already seen it in muar, thereafter JB & now u said already in Batu Pahat

i heard there ghost live in the bottom of the lake

Heard my dad say when the mine is still in operation u can see the big lorry like matchbox size only. He told me about it last time when we first went for the boat ride in the mines.

Silver Arapaima is the ferocious type... those black black ones are more gentle... i only saw one Silver type at Batu Pahat fish shop... i throw one 20cents coin into the pond and the fish straight away turn around trying to snap at watever disturbs the water... the owner told me is Arapaima... at first i thought is Toman...

Those black ones are gentle... i can touch them from head to tail while they swim past me....