"As we are talking about very big investments, I request that you make additions to the materials concerning the construction of the eastern border that would shed light on the reasons and grounds for choosing the solution for the eastern border, and present alternatives allowing to solve one problem or another along with their cost and effectiveness," Holm wrote in his letter to Minister of the Interior Andres Anvelt (SDE).

The chief auditor said that his concern was caused by the content of the materials presented to the Cabinet which do not explicity detail for Cabinet members why these particular types of structures must be built on the eastern border, or compare the effectiveness of various solutions in achieving specific objectives in combined effect with their cost.

"The materials only address one technical solution for the construction of the eastern border and its cost," Holm noted. "Materials have been presented to members of the Cabinet in a similar structure since 2015, when the topic of the construction of the eastern border was added to the Cabinet's agenda."

In the auditor general's opinion, the information concerning the eastern border that has been presented at this point does not allow for the assessment of the effectiveness of the construction of the eastern border in solving the problems cited as the reason for the construction thereof. "For instance, how much illegal border-crossing or smuggling can be reduced compared to the present when one or another amount of money is invested," he added.

As no alternatives together with their costs have been presented to the members of the Cabinet, they have not been able to make a well-weighted and -informed decision concerning Estonia's national border, Holm said.

He added that making different options available to Cabinet members was especially important in the current situation, in which it has turned out that the construction of Estonia's eastern border is going to be significantly more time- and cost-intensive than originally planned in 2015.

The auditor general also recommended that the rationale behind the construction of the eastern border be clarified to members of the Riigikogu as well.

The Estonian Cabinet is set to examine a plan for the full construction of the infrastructure and surveillance system of the Estonian border and thereafter make a decision regarding the plan going forward. According to the materials presented to the Cabinet, the construction and maintenance of Estonia's eastern border as currently planned is to cost an estimated €320 through 2026.