If I were Newtohk, I would give John Luciw - (pronounced as loo chew) a call, he runs / co owns Asiaxpat and inform him of the scammers activity on his site.
He's a pretty decent guy, so he might be able to dig up IP information that the classified advert was was logged under, any past advertising activity etc etc or extra info that might aid the police, should they be involved...
Good luck, hope you catch the creep....