Looking for AV software with a programatically accessible API

I am currently working on upload functionality for the website I develop and I am currently investigating for an AV product that allows access via an API (Windows server running, code will be running in .net or a com object), so we can scan files as they are uploaded (ideally the byte stream in memory).
The only product I have found so far is the Symantec Scan Engine.

I know I can write a com object that accesses commandline interface (we already have Symantec AV available), but am investigating this alternative as well.

Any suggestions/comments welcome, thanks.

 

every scanner used by virustotal.com and similar sites should match your requirements with the exception that scanning generally can't start until after the entire file has arrived...