The Ertzaintza, the autonomous police force of Spain’s Basque Country, said the woman was taken into custody on suspicion of homicide. The victim has been identified as a 67-year-old man of European origin.

In a statement, police said officers responded to a report of a suspected homicide at a residence in the Uribarri neighbourhood of Bilbao.

“Officers found the body of a man inside, showing clear signs of having suffered a violent death,” the statement said.

The woman, described as being of Latin American origin, was present at the residence when officers arrived. According to police, she confessed to killing her partner and was subsequently arrested.

The Ertzaintza has launched an investigation to determine the exact circumstances and motive behind the incident, which remain unclear.

A friend of the couple told People magazine that the news came as a shock.

“I’m in shock. We never expected this, and certainly not in the way it happened,” the friend said.

“When I finished work, I would always have a beer or a moscato on the terrace with them. They talked, they laughed. There has to be something behind this,” the friend added, noting that the couple appeared normal and did not seem to have a toxic relationship.

Police investigations are ongoing.