The OPLC has launched the probe after Dionne Knight was suspended for working as a consultant for West Ham during the Olympic Stadium bid process.
Knight has been suspended with immediate effect while the potential clash of interests is investigated.
The OPLC board, in charge of securing the future of the Olympic Park site, voted 14-0 in February to make the Hammers the first choice to move into the £486million stadium. The Hammers were in a head-to-head contest with Tottenham.
An OPLC statement read: "The Olympic Park Legacy Company has launched an independent investigation into its internal stadium procedures as a result of the allegations made concerning employee Dionne Knight.
"The auditors Moore Stephens have been appointed to carry out this investigation into our procedures. They have put together a team led by their specialist forensic unit.
"We are also investigating the nature of the consultancy work that Dionne Knight undertook without our knowledge or permission. An independent barrister will be instructed to conduct the employment elements of this investigation.
"We will communicate the outcome of both investigations when the work is complete. We remain confident that the integrity of our processes has not been compromised."