German police raided Volkswagen HQ and VW employee homes Thursday morning in a bid to discover the one(s) behind the car maker's decision to cheat on diesel emissions tests.

Three prosecutors and roughly 50 state criminal investigators searched Volkswagen offices and private homes in Wolfsburg, said Lower Saxony Senior Prosecutor Birgit Seel, reported Bloomberg. She noted it will take weeks to review the documents and electronic media investigators confiscated during the raid.

Volkswagen has vowed to support the work of prosecutors to the best of its ability, saying it handed over a "comprehensive collection of documents" to officials.

"We will assist the prosecutors in their investigation of this matter and the responsible people to the best of our ability. This serves the rapid and complete solution, in which Volkswagen has great interest," the company said, according to MarketWatch.

The raid comes as pressure on Volkswagen intensifies. The company's U.S. Chief, Michael Horn, faced U.S. lawmakers Thursday where he apologized on behalf of his company and admitted all wrongdoing falls solely on VW.

In Europe alone, VW will need to exchange or rebuild parts for about 3.6 million engines equipped with illegal software that only turned on during road tests - parts Volkswagen told German regulators it won't have until Sept. 2016.

In preparation to settle issues stemming from the tests, the company has set aside $7.3 billion, though analysts fear the figure could be far higher, reported CNN. Financial services company Credit Suisse estimates that at worst the issues may cost VW $87 billion - more than the cost of BP's oil spill that ravaged the Gulf Coast.