Rehe, who headed up Danske Bank's Estonian branch during the years when over €200 billion in potentially laundered funds are thought to have passed through the bank, left his home in the Pirita district of Tallinn at around 10.00 a.m. on Monday morning. He has not been seen since.

The PPA told ERR Monday evening that since they are concerned about his well-being, searches commenced very soon after he was last seen, including the usual routes he would have walked the dog. They also said that no third party is thought to be involved in the disappearance.

Valdo Põder of the PPA's Northern Prefecture said that Rehe would often take his dog for a walk at that time of day. However, the dog was left at home, as well as his phone.

"We have reason to believe that his life and health may be in jeopardy at this time," Põder told ETV current affairs show Aktuaalne kaamera.

Around 40 people were involved in the police search on Monday evening, almost half of them volunteers, and tracker dogs and drones have reportedly also been used.

Rehe is 180 cm tall, with short, gray hair, and was reportedly wearing a black sweatshirt and black pants with a "Collistar" logo, and white-soled, black sneakers, when he was last seen.

The PPA asks anyone with information on Aivar Rehe or his whereabouts to call them on 112.

Download the ERR News app for Android and iOS now and never miss an update!