In a post on social media, Ligi, who has previously served in serveral ministerial positions, including as Minister of Defence and Minister of Finance, wrote that prior to Kohver's abduction, the Estonian government did not consider it polite to start reinforcing the border as long as the border agreement with Russia had not yet been ratified. He also noted that estimates for the cost of the border project were about ten times lower than has been recently suggested.

"This absence of calculations also demonstrates that a plan to build infrastructure on the border actually did not exist," Ligi said. "With the abduction of Eston Kohver, the argument of politeness disappeared and the plan took shape. The current, adjusted estimate may be gilded, however. We have to examine whether only the best choices have been made in it."

It was announced on Thursday that, according to the PPA's calculations, the construction of Estonia's eastern border will cost 2.5 times more than initially planned, with the total price tag jumping from €79 to €197 million.

Minister of the Interior Andres Anvelt (SDE) ordered an internal audit launched to determine the reason for the drastic increase in cost.

On Sept. 5, 2014, ISS officer Eston Kohver was abducted by Russian agents under disputed circumstances at a location not far from the Estonian-Russian border and later sentenced in a Russian court to 15 years in prison for alleged espionage.

On Sept. 26, 2016, he was exchanged on a bridge crossing the Piusa River at the border checkpoint of Kunichina Gora for Aleksei Dressen, a former ISS employee sentenced in Estonia in 2012 to 16 years in prison for relaying sensitive information to Russia.