A former tech client of Thelen Reid Brown Raysman & Steiner has filed a malpractice complaint against the firm and one of its partners and contends the firm concealed that it was simultaneously working for a key competitor.

Delaware-based IVI Smart Technologies Inc. and two subsidiaries claim that Thelen, led by San Jose, Calif., partner David Ritchie, “actively assisted” the competitor in the repeated theft of intellectual property resulting in an alleged drop in the companies’ market capitalization from $200 million to $20 million, according to the complaint.