Forensic report: Chemical poisoning killed German family in Istanbul

Turkish authorities on Thursday confirmed that chemical poisoning killed a German family earlier this month in Istanbul.

Prosecutors said a forensic report found the cause of death for the family of four was an insecticide used for pest control in the family's hotel.

There was no evidence of food poisoning, which was initially suspected after the family, which had Turkish roots, fell ill while on holiday in Istanbul in mid-November.

Six people who were arrested during the investigation, including the hotel owner and the owner of the pest control company, remain in custody.

Four suspects have been released. Authorities had previously detained street food vendors who served food to the family.

The Istanbul public prosecutor's office did not disclose which poison killed the family, from the German port city of Hamburg. The state news agency Anadolu reported on Wednesday that the toxic gas phosphine was detected in the hotel.

Aluminium phosphide is frequently used in pest control. When it comes into contact with water - even humidity in the air is sufficient - the toxic gas phosphine is produced. The gas damages the body cells of mammals and, in larger concentrations, prevents the transport of oxygen in the blood.

In humans, phosphine can lead to symptoms such as a dry cough, vomiting, liver and kidney dysfunction - and can be life-threatening if inhaled.