Police suspect four people of aggravated fraud at the listed machinery company Cargotec.
The pre-trial investigation suggests that four people tricked the company into paying millions of euros into accounts connected to foreign companies over fifteen years starting in 2002.
Over that period the quartet are believed to have transferred some 14 million euros in total. An internal investigation uncovered the suspected fraud, and the police investigation began in 2018.
Investigators believe they issued fake invoices to get the company to transfer cash. One of those suspected of involvement was remanded in custody for nine months while the probe was completed.
Police say two of the four are Finnish citizens, while two are citizens of another EU country. The case is now with western Finland prosecutors for consideration of charges.
The firm has operations in Tampere, among other locations, and in 2018 its turnover was 3.3 billion euros.
It has some 12,000 people on its payroll.
Cargotec has previously confirmed that the suspected fraud involved their Macgregor subsidiary, which sells maritime freight equipment.