A crypto-savvy brother-sister team has been accused of running a $124m scam on investors in a crypto-mining operation purported to be one of the biggest in the world, but that was virtually worthless.

Federal prosecutors say the pair talked a big game about their Ormeus Coin operation, buying ads in Times Square, issuing white papers and staging roadshows and online seminars claiming it was backed by a $250m crypto mine that generated $5m in revenue per month.