20% return per year. Too good to be true?

I agree with ablrateandy - you've got to look under the hood and make your decision on the basis of the investment opportunity being offered.

The high rate of return being offered, on its own, is not proof positive that this is some kind of scam. In this case, stub8535 based on the evidence you've since dug up, it probably is.

But there are plenty of perfectly legitimate investment opportunities in the P2P & Crowdfunding space, giving investors access to niche segments of finance like invoice factoring and real estate bridge lending which can indeed deliver those high double-digit returns.

I wrote an article about why this is the case some time ago (spoiler alert: it all has to do with the convergence of regulation and technology). See link below.
www.propertycrowd.com/high-yield-with-capital-preservation-asset-backed-debt-could-mean-having-your-cake-and-eating-it-too/