BBC News via AP
This framegrab made available by the BBC on Monday May 2, 2016 shows creator of the Bitcoin, Craig Wright speaking in London.
In 2011, the pair founded a Florida-based firm called W&K Info Defense Research LLC, which was engaged in bitcoin mining and software development and research. Kleiman owned between 50 and 100 percent of W&K, the lawsuit said.
It claims that the Kleiman estate owns the rights to $5,118,266,427.50 worth of bitcoin and IP rights.
The filing says it is “unclear” whether Wright, Kleiman or the two together were responsible for the cryptocurrency’s creation. But the document adds that it is “undeniable” that the pair was involved in bitcoin “from its inception,” and that they acquired a “vast” number of bitcoins from 2009 to 2013.
It alleges that Wright fraudulently created at least three contracts and used a computer-generated signature to lay claim to bitcoins mined by Kleiman.
The case is being represented by Velvel Freedman and Kyle Roche of law firm Boies Schiller Flexner LLP.
Wright serves as chief scientist for blockchain firm nChain. CNBC contacted Wright on Twitter, and sent a request for comment to nChain, but neither was available at the time of publication.