WPP has had no further requests for information from Britain's financial watchdog after answering initial questions about the firm's investigation into Martin Sorrell, its recently departed chief executive, a company spokesman said.
WPP, the world's biggest advertising group, released a statement on April 3 to say it was investigating an allegation of personal misconduct against Sorrell, its founder and CEO for 32 years.
The Financial Conduct Authority (FCA) then wrote to WPP to ask if there was any more information it could share at that time.
Sorrell denied the allegation, but quit 11 days later, saying the disruption was putting too much pressure on the business.
"We had a call from the FCA after the Wall Street Journal article and our first announcement to ask if we could share any further details," a WPP spokesman said.
"We advised that we had satisfied all of our disclosure obligations and there was no additional information we needed to share. They were aware that we were ensuring we were discussing obligations with our legal advisers. They have not made any additional requests."
The FCA says it is the responsibility of listed companies to ensure they identify potential inside information and take steps to disclose it appropriately to the market.
"The FCA routinely contacts firms or their advisers to clarify press commentary, announcements and events and did so in this case," a spokesman said.
Shares in WPP initially rose in the days after the first statement before they fell 7% on the Monday after Sorrell's resignation.