A legal battle between the managers of Xfund, a venture capital firm with ties to Harvard University, New Enterprise Associates and venture capitalist Jim Breyer, entered a newly intense and bitter phase.

Hugo Van Vuuren, co-founder and general partner of Xfund, sued his partner, Patrick Chung, for breach of fiduciary duty, defamation and fraud. He also demanded a jury trial and damages to be determined at trial.

The complaint, filed Friday in Santa Clara County Superior Court, is the latest twist in a drama that has publicized in-fighting in a corner of the notoriously private venture capital community.

According to a copy of the complaint provided by a representative for Van Vuuren’s legal team, Van Vuuren, Xfund employees and the firm’s existence were compromised when Chung "fraudulently amended" partnership agreements to give him control. Before that, the two had equal voting power over Xfund decisions, the lawsuit says.

Van Vuuren signed the new agreements "without reviewing them," believing he was signing a document related to a separate matter, according to the filing. Chung e-mailed the document to Van Vuuren in late 2014 and only referred in the message to the other matter. The complaint alleged that Chung fraudulently induced Van Vuuren to sign the document against his interest.

The lawsuit also claimed Chung’s investments for Xfund have been unprofitable and that he spent the firm’s money on "unnecessary expenses." The complaint also said that in 2014 Chung was fired from New Enterprise Associates due to "behavioral issues and poor investment performance."

A spokeswoman for Xfund wrote in an e-mail that Van Vuuren’s allegations are “bewildering” and “lack any basis in truth.”

Firings, accusations

The origins of Xfund began in 2011 with Van Vuuren, an entrepreneur serving as an expert in residence at Harvard, and New Enterprise Associates, where Chung worked as a partner after graduating from Harvard’s law and business schools. Xfund’s early mission was to find and back startups developed through Harvard’s School of Engineering and Applied Sciences.

By mid 2012, other top VCs Accel Partners, Breyer’s firm Breyer Capital and Polaris Partners joined as limited partners and took seats on Xfund’s investment committee. In 2014 Chung left New Enterprise Associates to take a full time role in a 50-50 partnership with Van Vuuren in Xfund.