Mark Zuckerberg’s backyard privacy showdown has grown more tangled with competing claims about a mysterious African prince and a private eye accused of bullying a witness.

The Facebook Inc. founder is accused in a real estate developer’s lawsuit of reneging on a promise to introduce him to Silicon Valley’s elite as part of a $1.7 million deal that ended plans for a mansion with a view into the 31-year-old billionaire’s bedroom.