Ninety-five-year-old Rahmi Koc, honorary chair of Turkey’s largest conglomerate Koc Holding (IST: KCHOL), has been placed under investigation after making an off-colour joke with suggestive remarks about a Kurdish woman at the opening of a hospital.

Since video of the June 5 incident at Izmir American Hospital in Izmir spread on social media, several businesses connected to Koc, including a bank branch and two automotive sale and rental outlets, have been shot at.

On the other hand Bilal Bilici, a member of parliament for the opposition Republican People’s Party (CHP), sided with those who said an investigation was taking matters too far and would damage Turkey’s renewed appeals to foreign investors to make the country an investment base.

Bilici said: “Imagine if the US Department of Justice opened an investigation into Elon Musk, Warren Buffett or Richard Branson if they made a joke. It shows how capricious and arbitrary the rule of law can be in Turkey.”

In video clips, Koc, who headed the company from 1984 to 2003, is seen laughing with former prime minister Binali Yildirim, 70, after telling the joke about a Kurdish woman who spoke to a doctor about a medical complaint. In Koc’s telling, after the doctor tells her to undress behind a curtain, she replies: “Doctor, you undress first.”

Prosecutors in Izmir were quick to initiate an investigation into an alleged offence of “publicly insulting a segment of the public”.

Justice minister Akin Gurlek, formerly the chief prosecutor of Istanbul, responded to the situation by saying that “the scales of justice do not weigh according to anyone’s wealth, title or status”.

Koc apologised for his remarks, which came at the end of a week of celebrations to mark the conglomerate’s centenary. The holding has interests ranging from oil refining and finance to carmaking and healthcare.

Rahmi Koc’s unwelcome moment in the spotlight will also not have gone down well with the many Kurds in Turkey disappointed at the slow pace of talks designed to bring a permanent peace between Turkey and the politico-militant Kurdistan Workers’ Party (PKK) and raise the level of Kurdish minority rights.