A six-week-old baby was found dead alongside a four-year-old girl and a couple in an apparent murder suicide in a flat in Gibraltar.
Police said the four people are believed to have belonged to the same family.
Officers were called to the apartment in the Boschetti's Steps area at 11.35am on Monday.
They found a 31-year-old man of British nationality, a 37-year-old woman of Spanish nationality, a four-year old girl of Spanish nationality and a baby girl who was six weeks old.
Detectives and forensic officers are working in the flat and the area remains cordoned off.
A spokesman for the Royal Gibraltar Police said: "It is believed that all the deceased belong to the same family.
"However, there are still inquiries being conducted to locate close relatives of the family and as you may understand it is for this reason that the identities of the deceased are not being disclosed.
"At this present moment in time, a full investigation is being conducted by officers of the serious crime unit to establish the cause surrounding the untimely deaths of this young family and are encouraging anyone who maybe able to support the investigation to contact the duty officer of the Royal Gibraltar Police.
"Presently, we are not looking for anyone involved in this very unfortunate event, but the investigation will be thorough and detailed drawing in on the expertise of other professionals.
"Her Majesty's Coroner has already been informed and has visited the scene."
Spanish media reported that the family had been living in Spain and had only recently arrived in Gibraltar.
The British man involved was originally from Liverpool, according to police sources quoted by El Mundo newspaper.
The newspaper said the four-year-old girl was believed to be the woman's daughter from a previous relationship, while the baby had been born in Spain.
