What to do if my neighbors suspect my tenants are drug dealers?

[Scott K.]

I own a property in Hawaii, 5000 miles away from where I live in Virginia. I lived in Hawaii for 8 years and am waiting for the high season (this Winter) to sell my house over there. In the meantime, I rented my house to a local Hawaiian couple for 8 months.

One of my neighbors called me today and said that there are a lot of people coming and going from my house in Hawaii, people only stay for a few minutes then go. My neighbors said they are 99% sure there is some sort of drug operation that the tenants are doing out of my house in Hawaii. My tenants tell me they have a lot of relatives that visit them.

I have no proof of a drug operation, and neither does my neighbor. My neighbor says it's just a lot of suspicious activity.

What should I do?

EDIT: Something also to consider -- I have a lot of my own personal stuff locked in the garage and a downstairs room of the house, including my truck, tools, and personal items. If it turns out these tenants are doing something illegal and get raided, I can't afford to lose my truck and personal items.