The details of Mr. Thiel’s arrangement to support Mr. Bollea’s case are protected by a confidentiality agreement and could not be learned.

A Florida jury awarded Mr. Bollea $140 million in March over a sex tape Gawker published in 2012.

The revelation of Mr. Thiel’s involvement in Mr. Bollea’s case, which has captured headlines this year for its salacious disclosures, came a day after Nick Denton, Gawker’s founder, was quoted in The New York Times as saying that he believed that Mr. Bollea’s case was being supported by a mysterious third party.

“My own personal hunch is that it’s linked to Silicon Valley,” Mr. Denton said.

Mr. Denton called on Mr. Bollea’s legal team, which refused to comment on the possibility of an outside funder, to disclose the backer.

Mr. Thiel’s identity was first reported late Tuesday by Forbes magazine.

There is nothing illegal about funding such legal cases; there is an entire industry known as litigation finance that often helps invest in and financially support lawyers working on contingency in small and large cases. It is not common for a lawsuit to be backed by a third party that may have other motives.