Switzerland will probe state-owned arms maker Ruag AG after its failed attempt to sell almost 100 tanks that would eventually have been used by Ukraine in its war against Russia.

The country’s defense ministry has asked external auditors to investigate the controversial deal with Germany’s Rheinmetall AG, which was eventually blocked on the ground that it would violate Switzerland’s status as a neutral country. It will also examine whether the relation between the company and the government needs to be reformed, the ministry said in a statement on Monday.