[Red_Tarsius]

> Given the situation, offer they pay you a reasonable fee for the problem to go away.

I'm afraid the investors would read it as some kind of bribe and the culprit could sue him for such accusations. He doesn't have a contract to support his claims, the e-mail would cause more trouble than it's worth it.

[charlesdm]

Doesn't he have e-mails to prove his case? Those are often as good as a written contract.

At the very least, they should know the kind of person who they invested money in.

In addition, they invested in this company to make money, no? In the event they are not interested in fixing it now and you have some valid evidence then you can always sue if they make it big/sell it.