The probe into Orhan Turan, head of the influential TUSIAD business and industry association, was opened by Istanbul's chief public prosecutor following remarks he made last week about the justice system, Anadolu news agency said.

He is under investigation for "seeking to influence the judiciary" and "spreading misleading information" -- the same charges levelled at Omer Aras, another top TUSIAD figure who was named in a probe on Friday.

Both were taken by police on Wednesday to appear before an Istanbul judge.

At issue are critical remarks the pair made at TUSIAD's annual general meeting last Thursday.

In his speech, Turan said Turkey would not be able to address its problems without restoring the rule of law, noting the recent wave of detentions of journalists, politicians and others for making critical remarks, as well as the removal of elected opposition mayors.

He also said the lack of accountability following disasters where many lives were lost, be they earthquakes, fires or accidents, had impacted public perception of the justice system.

"Behind these problems lies a loss of trust in the rule of law," he said.

Aras likewise criticised the legal probes into Istanbul's powerful opposition mayor Ekrem Imamoglu -- Erdogan's biggest political challenger -- saying such matters "created anxiety in society and shook trust".

- 'Act like a business association' -

Later that night on X, Justice Minister Yilmaz Tunc slammed "attempts to interfere with the justice system", promising "the strongest possible response".

On Tuesday, TUSIAD published a statement on its website saying Turkey could only ensure "lasting economic development with a state of law based on human rights and the principle of participatory democracy".

The next day, Erdogan fired a direct shot across TUSIAD's bows, warning it not to overstep the mark.

"If you are a business association, you will learn to act like one. You will not provoke the nation, you will not provoke state institutions nor try to pressure the judiciary," he told delegates from his ruling AKP on Wednesday.

The move to investigate top TUSIAD figures was denounced by the pro-Kurdish DEM, the Turkish parliament's third party, which described it as "an attack on freedom of expression".

"We ask the government: should everyone be silent and only you speak? Will the police visit anyone who expresses an opinion you don't like?" wrote DEM co-leader Tuncer Bakirhan on X, urging it to "turn away from this error and stop violating the law."

The latest probe came a day after the government said 282 people had been detained in five days in an operation targeting those with suspected "terror" ties. Istanbul's public prosecutor said it included DEM party members, journalists and left-wing figures.