Problem Marshalling struct from C# to C++ void*

Question

I'm working with legacy code base that has some C++ that's been converted to managed. I'm inheriting my C# class from the C++. I'm overriding a function that makes a call to a function that's signature contains a void* as a parameter. I can't seem to find anything in C# that matches it. (I've tried several things, including IntPtr and ref.)

C++
WriteStructure( String path, void* structure, unsigned int size )

Does anyone have a suggestion?