shady business

I had just told him that I thought an argument he was dismissing was really about shady business dealings.

We got mixed up in a shady business, explained Jackwell, with a look of misery on his face.

If he's engaged in a shady business—if he's cooked up a deliberate scheme to trap you—he won't come near you.

The doctor's a fine old chap, and I'd hate to think he was mixed up in any shady business.

The two young men became mixed up in a rather shady business deal, which was more of Hayden's weaving than Kendrick's.

He thought he might improve his situation and went in for a shady business.