By Dominique Vidalon and Matthieu Protard
PARIS (Reuters) - France's AMF stock market watchdog is in the midst of a formal investigation into criticism made by U.S. research firm Muddy Waters against French retailer Casino (PA:CASP) which should last a few more months, a source close to the matter said on Wednesday.
"The probe has been under way since the start of the year. The AMF is conducting in-depth investigations on a complex matter. It implies checking the communication of the two protagonists in the case and assessing whether there has been a violation or not," the source told Reuters.
In December 2015, Muddy Waters had criticized Casino's accounting practices, saying the supermarket retailer was "dangerously leveraged" and managed for the short-term, prompting the worst slide in seven years in Casino's stock price.
Casino has rejected Muddy Waters' criticism and, having raised the issue with the AMF, said it reserved the right to take legal action.