The Energy Department is denying that Energy Secretary Rick Perry knew that President Donald Trump had been pushing for a political investigation in Ukraine.

Energy Department spokeswoman Shaylyn Hynes issued the denial Wednesday in response to U.S. Ambassador Gordon Sondland’s testimony before the House impeachment panel.

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Sondland tells impeachment investigators that Trump attorney Rudy Giuliani had let Perry know that Trump wanted Ukraine to publicly promise to investigate a natural gas company that had employed the son of presidential rival Joe Biden.

The Energy Department says Perry never heard any such mention from anyone before the Trump’s conversation with the Ukrainian president became public. Hynes says Perry talked to Giuliani only once at Trump’s request.

Perry so far has declined to appear before the committee to testify.