Finland's National Bureau of Investigation (NBI) is investigating a case regarding a Finnish company's suspected sale of substandard defence equipment to Ukraine, as well as serious financial crimes.

According to an NBI press release, the Finnish firm signed a contract with Ukraine's defence ministry in 2022, agreeing to deliver 10,000 bulletproof vests to the Ukrainian defence forces in a deal valued at around 5.7 million euros.

The NBI suspects that the quality of 5,000 bulletproof vests that were eventually delivered to Ukraine in the summer of 2022 did not meet the standards agreed to in the contract.

According to Detective Inspector Mikko Laaksonen, the preliminary investigation was initiated after Ukraine asked for assistance with the matter.

"In order for the case to be investigated, there was close cooperation with authorities in Ukraine during the preliminary investigation," Laaksonen said in the release.

The firm's manager is suspected of aggravated fraud, aggravated embezzlement and aggravated money laundering, according to the NBI.

The case is expected to be forwarded to prosecutors for consideration of charges this summer.