A dispute with a real estate developer is turning into a major headache for Facebook founder and CEO Mark Zuckerberg.In November 2012, the developer, Mircea Voskerician, told Zuckerberg that he planned to build a 9,600 square foot house behind the very private Zuckerberg’s home in Palo Alto, Calif.

Mark Zuckerberg in ugly lawsuit

Then Voskerician made Zuckerberg an offer: He proposed selling Zuckerberg a small piece of the property to give him the privacy he wanted.

Voskerician said the house would have a view directly into Zuckerberg’s home, including the master bedroom.

In an email, a financial adviser to Zuckerberg called Voskerician’s offer an “obscene proposal.”

Zuckerberg’s wife, Priscilla Chan, wrote: “It’s stuff like this that makes me so sad and angry.”

A short time later, Zuckerberg struck a deal with Voskerician to buy his contractual rights to the entire property.

Voskerician claims he had a competing offer for $4.3 million but sold Zuckerberg those rights for $1.7 million because Zuckerberg promised to introduce him to “influential people” in Silicon Valley.

According to the New York Times, at the end of that meeting, John Forsyth, Voskerician’s real estate agent, says Zuckerberg’s real estate agent Terri Kerwin told him: “Mark always keeps his promises.”

In May 2014, Voskerician filed a lawsuit against Zuckerberg, claiming the billionaire tech mogul stiffed him on that promise. He was deposed this week in California.

Emails between Zuckerberg and his inner circle suggest he had no intention of helping Voskerician other than in a “light” way.

“How do we make this go away?” a Zuckerberg adviser wrote to his real estate agent. “MZ is not going to take a meeting with him … ever.”

Zuckerberg’s lawyers say Voskerician is trying to extort and embarrass their client.

Now, according to the New York Times, Voskerician is trying to get access to Zuckerberg’s personal finances and net worth.

Facebook does not as a matter of policy comment on Zuckerberg’s personal affairs.

Zuckerberg’s attorney Patrick Gunn told the New York Times that “the claims asserted in the lawsuit have no merit and my client intends to defend them vigorously.”