Canada's largest cryptocurrency exchange is unable to access millions in digital currency following the sudden death of its founder, Gerald Cotten.
Quadriga has filed for creditor protection and estimates that about C$180m (€120m) in cryptocurrency coins is missing.
It has not been able to locate or secure its cryptocurrency reserves since Mr Cotten died in December.
In court documents filed with the Nova Scotia Supreme Court, Mr Cotton’s widow Jennifer Robertson said that the laptop on which he "carried out the companies' business is encrypted and I do not know the password or recovery key".
"Despite repeated and diligent searches, I have not been able to find them written down anywhere," the affidavit stated.
Ongoing efforts by private investigators have had only "limited success in recovering a few coins" and some information from Mr Cotten's computer and phone.
According to the affidavit, the majority of the cryptocurrency was kept by Quadriga in a ‘cold wallet’, located offline and used to secure cryptocurrency from hacking or theft.
Ernst and Young are expected to be appointed as independent monitors to oversee the proceedings.