Samira Islam, 20, died on Friday after she was found unconscious in a locked room by police on July 26. Her father, Rafiqul Islam, 51, a taxi driver, and his 16-year-old son, Mahiqul, also died in the rented apartment in the eastern city of Sylhet. Samira Islam’s mother, Husnara, 45, and eldest son, Sadiqul, 24, were hospitalized and said to be recovering well. They have since been released from hospital, a source told the BBC. The family, from the Riverside area of Cardiff, were on a two-month holiday visiting relatives in the country. After eating dinner on Monday July 25, the family was found unconscious the next day by relatives who raised the alarm after hearing noises from the flat and tried unsuccessfully to open the door. “Our main suspicion is that they were poisoned,” Supt Farid Uddin said, adding that all family members had slept in the same room, the doors were locked and there was no sign of forced entry. Samira was previously in critical condition and on life support in hospital. Police said they had collected samples to be tested in a laboratory to better understand the cause of death. “Our investigators are talking to the relatives of the victims. So far we don’t think they have enmity with anyone,” Uddin said. Masudul Amin, the investigator, said: “We are also speaking to the relatives who were in the flat and other residents of the building. No one has been arrested or detained for this murder.” Those who knew the family in Cardiff were shocked and in disbelief at the news. Muhibur Islam, an employee at the Jalalia Mosque and Islamic Education Center, has known the family for many years. He described them as well-loved in Riverside, the center of a Bangladeshi community in Cardiff. “It is very terrible,” said Islam. “It’s very tragic, hard to accept.” Islam said Rafiqul Islam’s mother and two brothers had flown to Bangladesh. “The circumstances are not clear. We pray that those who have survived will pull through,” he added. “We are praying for all of them.” Subscribe to First Edition, our free daily newsletter – every morning at 7am. BST The family were described as “quiet” and “nice” and told to “do their own thing” by a neighbor who has lived near them for more than 25 years, who asked not to be named. Kanaya Singh, Labor councilor for Riverside, said everyone in the community he had spoken to spoke highly of the family. “There is also a lot of concern because many people from Riverside go to Bangladesh on a regular basis. I hope the authorities can get to the bottom of this as quickly as possible.” On July 28, hundreds of people lined the streets of Sylhet for the funeral of Rafiqul and Mahiqul, according to the BBC.