An American couple has been arrested in Spain on suspicion of reckless homicide after the badly decomposed body of a child was found at their family home in the northeastern city of Girona, police said Wednesday.

A 39-year-old man and a 38-year-old woman with American citizenship are in detention waiting to be questioned by an investigating magistrate, according to a police statement.

The arrest was made Tuesday at the couple's two-story apartment where they lived with their three children, police said. The father is an engineer, but it wasn't immediately clear what part of the U.S. the family came from or how long they had been living in Spain, police said.

The child's body was found lying on a bed, under several blankets, police said.

They said an autopsy had been ordered, but didn't say how old the child was.

Officers were called to the building by the apartment's owner who had gone to collect unpaid rent but detected loud noises inside and was denied access, news agency Europa Press said, citing police sources.

The U.S. Embassy declined to comment, citing the Privacy Act that provides safeguards against invasion of personal privacy through the misuse of records by federal agencies.

Police said the investigation to determine the circumstances of the child's death is ongoing.