A judicial enquiry was opened in France in June over the handling of the pandemic after formal complaints were lodged by civil groups and members of the public.
This was followed by the Court of Justice opening an enquiry in July.
The criminal investigation has a relatively limited scope and is looking at specific aspects, such as the alleged failure to put in place anti-virus protections at the workplace, to provide face masks to reduce infection, and to roll out testing to diagnose carriers of a virus.
Possible charges of involuntary homicide, involuntary injury, endangering life, failure to combat a threat and non-assistance to persons in danger are being examined.
The Court of Justice investigation – under which the searches were carried out – has a wider remit and can look at how political decisions were made.
French media reported that searches were carried out on Thursday morning at the homes and officers of France's Health Minister Olivier Véran and Director General of Health Jérôme Salomon.
It is understood that the investigation also concerns three people who are no longer in post – the former Prime Minister Edouard Philippe, former Health Minister Agnès Buzyn and former government spokesman Sibeth Ndiaye – and the current prime minister Jean Castex.
Véran, a former neurologist, arrived in post as health minister on February 16th this year, so much of the planning for the pandemic was done by his predecessor Agnès Buzyn.
She was drafted in at short notice to be the candidate for Emmanuel Macron's party in the race to be mayor of Paris after the former candidate Benjamin Griveaux dropped out when his sex tape was released online.
Véran's profile has steadily risen as the crisis progressed and he has become known for hand-drawing graphs during TV interviews to explain the latest developments.
France's health minister on TV drawing one of his trademark graphs ?? https://t.co/B7Add71LEB
— Emma Pearson (@LocalFR_Emma) October 8, 2020
Jérôme Salomon, a civil servant, is Director General of Health. Relatively unknown before the crisis he became the face of nightly TV briefings during the lockdown, explaining the latest epidemiological developments with his trademark calm and unemotional delivery.