Oil leakage problem

I have Honda Civic 95 ex model, it was going very fine few days before, but my car gas kit was got burn so I need to get it change by mechanic, but later on there was an oil leakage, I went back to mechanic for the same, he changed my car tapid cover seal, chamber seal, distributor ring, and two more seals did not remember the name but after all these efforts still I am facing the same oil leakage problem, even now mechanic said that he could not be able to find where oil is coming from, so any one have an idea, now what needs to be checked after the changing of all these things, waiting for reply