Norfolk Southern launches investigation into CEO Alan Shaw

The company said in a statement Sunday that the potential conduct was "inconsistent with the company's Code of Ethics and company policy."

"Norfolk Southern holds all its team members to the highest standards," the company said in its statement. "In line with the company's Code of Conduct and company policy, allegations of misconduct are thoroughly investigated."

The railroad company said it has retained outside counsel that will act independently to conduct the investigation.

"To ensure a fair investigation, the company and the board cannot comment further until the investigation is complete," Norfolk Southern said.

CNBC reported that three sources "familiar with the matter" said the Shaw investigation involved an inappropriate workplace relationship.

Shaw, who has worked as Norfolk Southern's CEO since 1922, faced a protest from a shareholder who wanted him fired over his response to the toxic derailment in East Palestine, Ohio , which made national headlines.