Oil pan gasket replaced 5 times to stop oil leak on 1995 Toyota Corolla

My mechanic has replaced the oil pan gasket 5 times to stop an oil leak and it continues. He already replaced the rear crank seal and the remaining leak is always by the oil pan. What else could be the source of the leak because clearly its not the gasket being sealed properly.

Asked by for the 1995 Toyota Corolla
You could have a leak in the oil pan itself or it could be your rear main seal is leaking