Here is further detailed information regarding CoinLab's lawsuit against Mt. Gox:

2013-05-02 Gawker article, "Massive Bitcoin Business Partnership Devolves Into $75 Million Lawsuit":
http://gawker.com/massive-bitcoin-business-partnership-devolves-into-75-487857656

Official court document, CoinLab, Inc. v. Mt. Gox KK & Tibanne KK (filed 2013-05-02 in Washington by CoinLab's attorneys at the law offices of Breskin Johnson & Townsend PLLC):
http://www.scribd.com/doc/139160091/Coinlab-v-Mt-Gox

Official contract between CoinLab, Inc. & Mt. Gox KK, "Exclusive License Agreement for the USA & Cananda", with signatures of Mark Karpeles, CEO of Mt. Gox KK & Peter Vessenes, CEO of CoinLab, Inc.:
http://www.scribd.com/doc/139181173/Contract-between-Mt-Gox-and-Coinlab