The chief executive of JBS, Wesley Batista, has been suspended as head of the world’s largest meat processor. He is being detained for questioning as part of an investigation into alleged fraud at some of Brazil’s largest pension funds.

He has been CEO since 2011. His brother Joesley Batista, who is chair of the company, is also being investigated. The potential removal of the two brothers in the company would be negative given the important role they have played in building the company into the largest meat processor in the world. Last year, JBS bought Northern Irish chicken procerssor Moy Park.

Shares tumbled 17% since Friday before recovering 6% on Tuesday.

This investigation comes at a particularly sensitive time for JBS, which announced a corporate restructuring in May with plans to list its shares in New York and move its international headquarters to Dublin. It may prolong or even derail JBS’s plans of becoming a publicly traded company in the near term.