The police are seeking to identify a man recorded by CCTV wearing a yellow jacket in connection with an attack on the head of the North Estonia Medical Center (PERH).
In the video, the man can be seen walking down a snowy street wearing a bright yellow jacket.
Urmet Tambre, head of the Northern Prefecture Criminal Bureau, told ERR on Friday: "It is crucial to identify this person." He urged people to call the police if they had any information.
The CCTV footage can be watched here and you can contact police on 5690 4272 or email firstname.lastname@example.org.
The attack took place while Talving was sitting inside his car outside PERH in Tallinn at around 7 p.m. on Wednesday, during which a liquid was thrown at him.
A well-known anti-masker and critic of coronavirus restrictions was detained by police in relation to Wednesday's attack but was later released.
Editor: Helen Wright