Site dropped from G's index

I think a 'competitor' may have done something

[oldskool79]

My site was a PR7 with close to 700 backlinks. These were all 'natural' links, no paid links or anything like that. There were 30,000 pages indexed with excellent rankings for many keywords.

On Sunday PR dropped to 0, no links show up, and no pages are in the index.

The only explanation I can come up with is that a partner of mine somehow got my site banned. About a week ago I found out he was cheating me out of money and cut off the partnership. Then this happens -- the timing seems too perfect.

Is there any way that someone could get another site delisted from Google? If someone did contact them, would they let me know about it or just remove my site? (Note: this ex partner doesn't have access to the site at all)

[WebFusion]

I would check the obvious stuff first, i.e. check for a robots.txt/meta tags that exclude google.