ComScore’s disclosure today that it couldn’t meet a self-imposed deadline to file financial reports for 2015 and this year’s Q1 sent its shares plummeting 19% today, touching a three-year low.

The audience measurement company says in an SEC filing that on February 19 its Audit Committee “received a message regarding certain potential accounting matters.” It launched a review with help from independent counsel and advisors.

On May 11  ComScore said it’s “working vigorously to complete its review,” and “expects to provide an informed update by June 27, 2016.”

But today the company said that although investigators “have completed a substantial amount of their factual inquiries,” they “require further time to evaluate the information collected and to reach and evaluate final conclusions.”

The company now says it will file its reports “as soon as reasonably practicable.”

ComScore said in March that it had failed to comply with NASDAQ rules requiring timely filing of financial reports, but planned to respond with a plan to regain compliance. That would give it until August 27 to file the reports.

In February comScore just completed a stock swap acquisition of Rentrak it announced in September, creating a digital and TV audience measurement power. Ad giant WPP owns about 18% of the company.