A crypto inventor has filed a legal malpractice lawsuit against Covington & Burling, claiming that Covington attorneys failed to provide “exculpatory evidence” to prosecutors in a federal criminal matter he was facing and later indicted for.

The malpractice suit was filed in Manhattan Supreme Court on Friday on behalf of Steven Nerayoff, an early adviser to the blockchain platform Ethereum network. The suit claims that he ”presented evidence of his innocence” in the criminal matter to Covington attorneys representing him, though was advised not to share it with prosecutors. The suit names Covington senior counsel Alan Vinegrad and partner Amanda Kramer as his lawyers at the time.