Tech billionaire Elon Musk was due to appear before French prosecutors for questioning ‌on Monday, as part of an investigation into X and its AI chatbot Grok that is set to further strain relations between the US and Europe over Big Tech and free speech.

It was not ​clear if Musk would attend the hearing.

The date was set in February when ​the Paris prosecutor’s cybercrime unit raided the French office of the social media ⁠platform in a probe related to fraudulent data extraction.

It was later expanded to ​include suspected complicity in the distribution of child pornography and the creation of sexual deepfakes.

While attendance at Monday’s hearing is mandatory, the authorities at this stage cannot compel Musk to appear.

Reuters could not reach representatives for Musk ahead of the summons.

In July, Musk denied the initial accusations and ​said French prosecutors were launching a “politically-motivated criminal investigation”.

The Paris prosecutor’s office declined to comment.

X ​has come under scrutiny from regulators and governments in several countries since Musk’s takeover of the platform, with ‌authorities ⁠examining issues including content moderation, data practices and compliance with local laws.

Prosecutors have said the centres on whether X’s algorithms distorted the treatment of content on the platform and whether the company improperly extracted user data, after complaints from French lawmakers and advocacy groups.

In a ​sign of the potential ​for the investigation ⁠to worsen already tense relations with Washington, the Wall Street Journal reported on Saturday that the US Justice Department sent a letter to ​the Paris prosecutor saying it would not cooperate in the probe, ​which it viewed ⁠as politically motivated.

The Paris prosecutor said it had no knowledge of such a letter, and added that “the French constitution guarantees the separation of powers and the independence of the judiciary.”

Former X ⁠CEO ​Linda Yaccarino and several other X staff have also been summoned ​as witnesses for questioning.

After such a hearing, authorities can decide to either shelve or continue the probe, and potentially ​place suspects under formal investigation.