Not clear exactly what plaintiff means by 'the investigation file'

Not clear exactly what plaintiff means by 'the investigation file'

Gelderland District Court March 22, 2023, IT 4243; ECLI:NL:RBGEL:2023:1575 (plaintiff v. De Volksbank) In this lawsuit, the plaintiff sued De Volksbank for processing personal data in various administrations and registers. The plaintiff claims that it is entitled to access this personal data and information about the source of this data. The Volksbank has indicated that the plaintiff can obtain inspection by filing a request for inspection. The plaintiff's attorney sent a letter requesting a further explanation of what information about the plaintiff was requested from third parties and what was done with it. The court ruled that the plaintiff is entitled to see the personal data processed by De Volksbank, including information about the sources of data not collected from the plaintiff. The plaintiff is also entitled to information about the consulted

https://www.itenrecht.nl/artikelen/niet-duidelijk-is-wat-eisende-partij-precies-bedoelt-met-het-onderzoeksdossier