Workers from Ukraine and Belarus could have been hired illegally to mend the Gediminas Hill, a landmark in Vilnius, according to the Financial Crime Investigation Service.
Fortification works on the hill involved companies registered in Lithuania and Poland under a Ukrainian national's name. A preliminary investigation found that the companies illegally hired workers from Ukraine and Belarus, forged documents, and doctored account books.
The companies are also suspected of tax avoidance and their director could have embezzled around €300,000, according to the Financial Crime Investigation Service.
During searches in the companies' offices, investigators found around €26,000 in cash intended for off-the-books salaries and notes proving the companies contracted illegal workers.
Suspicions have been brought against the companies' director, who was not named.
Fortification works were started after rains washed away parts of the hill, threatening its structural integrity. The Gediminas Hill Tower is an iconic landmark and one of the country's most recognizable symbols.