Police are investigating the unexplained deaths of 10 dogs at a “luxury dog hotel” in Woudenberg in Utrecht.

A member of staff found the dead dogs on coming to work on Saturday morning. Some of the dogs, which are left locked up alone at night with camera surveillance, were still alive and were rushed to a veterinary hospital.

“The owners of the dogs are extremely sad and have lots of questions which have not been answered yet. What happened here? Did my dog suffer?” lawyer Brigitte Roodveldt, who is representing a group of owners, told the AD.

“My worst nightmare has come true, my babies and best doggy friends are gone. Two dogs, this is a big shock,” one owner wrote on social media. The woman had tried the pension for a weekend “because of its good reputation”,  she said.

It is not clear what had happened but according to the duped dog owners, the pensionl owners are not to blame. “We are sure they would not have wanted this to happen and that this has hit them hard. In these types of cases there are only losers,” they told the paper.

A police spokesman said the police are being assisted in their investigation by the Dutch food and product safety watchdog NVWA.

The pension owners, who have started their own investigation, said they would not comment until more is known about the incident.