It seems you were right. It is apparently a scam alright! And big one!

I won 4.5 BTC there and issued withdrawn of 4.5 plus my deposit 1 BTC, totally 5.5 BTC. That is about 4K $ now! I've got email that the Bitcoins will be sent on next business day. When there were not sent I wrote them email.

They did not respond. But by mistake one of them sent me email apparently addressed to another man behind it. It says that he shoud decline my request because I "have a bonus". I wrote them again, but they never responded to me.

I am not sure what are they trying to pull off, but I did not use their bonus which they are giving automatically as you send deposit and you cannot say you don't want it and you don't request it, they just automatically add it as you deposit Bitcoins. But I was always betting only with my deposit and I always stayed positive only with my deposit.

It is total scam!

The site is hosted in Netherlands, but it seems people behind it are from Israel. Do someone know to which authorities in Israel and Netherlands should I report this scam? Thanks.