5 February 2026
The Arnhem-Leeuwarden Court of Appeal ruled that the costs of a private investigator’s report can be recovered from the maintenance recipient. This is happening more and more often.
This provision states that an obligation to pay spousal maintenance may end for the paying party if the alimony recipient remarries, enters into a registered partnership, or cohabits with another person as if they were married. The final phrase, “cohabiting as if married”, was added to the provision later and has led to extensive case law. The wording is somewhat vague, and it creates evidentiary difficulties for the maintenance payer.
The burden of proof for “cohabiting as if married” rests with the maintenance payer, and strict requirements apply to the substantiation of that claim. For this reason, maintenance payers increasingly make use of a private investigation agency. Such an agency investigates the relationship between the maintenance recipient and their new partner, and gathers evidence to meet the high threshold for proving cohabitation as if married.
Where the maintenance recipient fails to provide sufficient counter-evidence, the costs of the investigation are increasingly being recovered from them. Courts are also granting such claims more frequently.
In a judgment of the Arnhem-Leeuwarden Court of Appeal (ECLI:NL:GHARL:2023:209), the court ruled that the woman could reasonably be expected to have actively informed the man about her living arrangements with her new partner. She failed to do so and therefore acted negligently, which constituted an unlawful act. The court held that the consequences of this failure to inform were for her own account and risk. Since the woman’s cohabitation could not be established other than through an investigation by a private investigation agency, the costs of that investigation were regarded as part of the damage suffered by the man as a result of her conduct. As a consequence, the woman was ordered to reimburse the man for the costs of the investigation.
The maintenance payer faces strict substantiation requirements in order to prove that the maintenance recipient is now “cohabiting as if married”. Nevertheless, courts are increasingly willing to accept well-supported claims. The costs that may be necessary to obtain evidence, such as hiring a private investigator, can therefore more often be successfully recovered from the maintenance recipient.
Do you have questions about this article, or about the steps required for a successful reliance on Article 1:160 BW? Please feel free to contact us.
