Ernst & Young LLP resigned as auditor of the troubled server maker Super Micro Computer Inc.citing concerns about the company’s governance and transparency.

Ernst & Young has raised questions about the company’s commitment to integrity and ethics, according to a filing from Super Micro on Wednesday. The firing comes a month after the Wall Street Journal reported that the Justice Department had launched an investigation into a former employee’s claims that Super Micro had violated accounting rules. Super Micro has begun the process of identifying a new auditor, it added in the statement.