The Wall Street Journal Europe and local German media have reported that a probe into trading in DaimlerChrysler shares before Juergen Schrempp, chief executive, said he’d step down included a sweep of the offices of Rudiger Grube, a member of the company’s management board in charge of corporate development, and Hartmut Schick, head of corporate communications.

On Thursday, German prosecutors probing possible insider trading of Daimler stock searched the homes and offices of four people, including two DaimlerChrysler staff members. German media have said the search included the offices of executive board member Ruediger Grube, the group’s head of business development and of operations in China.

The Frankfurter Allgemeine Sonntagszeitung newspaper said Grube denied he bought into Daimler stock before Schrempp’s surprise announcement in July, which sent the stock 10 percent higher.

“This allegation is wrong,” the manager told the paper, adding that he had last bought Daimler shares in 2000. “I am angry if your own credibility gets hampered,” he said.

German state prosecutors and the country’s financial watchdog BaFin are investigating possible insider trading of Daimler shares before Schrempp’s resignation announcement.

BaFin has said it had concrete indications of improper deals in the firm’s stock before the announcement.

On Saturday, the Stuttgarter Nachrichten newspaper said DaimlerChrysler might have announced Schrempp’s exit too late.

Internal hints of the resignation had intensified up to five weeks before the firm’s statement to the German stock market, it said, quoting a letter from Stuttgart prosecutors.

The DCX share price jumped 10% following Schrempp’s shock announcement that he would step down.