A US Department of Justice (DoJ) competition probe into Google and other tech companies suffered a setback after the lead enforcement officer backed out due to a potential conflict of interest.

The New York Times reported assistant attorney general Makan Delrahim had withdrawn from the investigation. A DoJ representative told the publication Delrahim “revisited potential conflicts with previous work” and, with the help of the DoJ’s ethics office “decided that he should now recuse himself” out of an “abundance of caution”.

Google is part of a broader investigation opened by DoJ competition officials in July 2019 into whether social media companies and online retailers were hindering consumer interests by abusing dominant market positions in search and advertising.

The DoJ said associate deputy attorney general Ryan Shores and deputy assistant attorney general Alex Okuliar will oversee the probe going forward.

Before being appointed at the DoJ in 2017, Delrahim worked as a corporate lawyer and lobbyist who, among other things, helped secure regulatory approval for Google’s acquisition of internet advertising company DoubleClick in 2007. He also represented other tech and telecoms players including T-Mobile US, AT&T, Apple, Qualcomm and Microsoft.

The announcement came as DoJ officials prepared to meet with state attorney generals, who are conducting a separate competition investigation, to share information and discuss the potential for collaboration on action against Google. Reuters reported the meet was set for today (4 February).