Deutsche Börse AG CEO Carsten Kengeter met with German Finance Minister Wolfgang Schäuble to discuss a potential merger with London Stock Exchange Group Plc ahead of his controversial purchase of the German exchange operator's shares, which triggered an insider trading probe, Reuters reported.

Excerpts of a document by Linklaters, Deutsche Börse's external counsel, showed that the meeting between Kengeter and Schäuble took place Nov. 3, 2015. Days before the meeting, Kengeter sent a paper to the finance ministry in a bid to learn how politicians would react to a potential merger of the company with LSE, according to the Oct. 13 report.

Kengeter, who bought Deutsche Börse shares just two months ahead of the announcement of the now-failed merger talks with LSE, has maintained that the purchase was a "moral duty" and was part of a company remuneration program.

The news comes a month after Deutsche Börse agreed to pay the Frankfurt Public Prosecutor €10.5 million in fines to settle the insider trading probe. As part of the settlement, Kengeter would pay a personal fine of €500,000.