They were taken to the hospital, but the children, aged 3 and 6 years, died on Thursday, while the mother died the following day, according to the Minister of Justice.
The regional director of the Turkish Ministry of Health in Istanbul, Abdullah Emre Gönér, stated on the platform "X" on Friday night, that the father is still in "critical condition".
Several media reports discussed the types of food the family is believed to have consumed.
However, investigators discovered that a room on the ground floor of the hotel had recently been sprayed with insecticides, according to what was reported by the website of the newspaper "Hürriyet" on Saturday.
The police had detained a hotel employee and two pest control workers, bringing the total number of people detained in connection with the incident to seven.
The police said that the family is Turkish but lives in Germany, and that they came to Istanbul for a vacation.
