A couple and their three children were found dead in their house at Githurai 45.
According to Ruiru OCPD Phineas Lingera police suspect that the family was a victim of carbon monoxide poisoning.
A police report indicated that neighbours became suspicious after the caretaker - Jacob Karumba - and his family were not seen leaving their house for a while.
When they opened the door - which was not locked - they found the bodies of Jacob Karumba, 32, his wife Doris and three children aged eight, six and three months old.
The report says a charcoal jiko was found in the house and it is suspected they died of suffocation.
Experts warn against keeping a burning jiko in the house because poisoning happens in humans when carbon monoxide is trapped in poorly ventilated and contained spaces.
The gas emitted is a silent killer as it cannot be seen yet it kills due to toxic effects to the circulation system after it is inhaled.
After breathing in carbon monoxide, it enters the blood, mixes with the red blood cells haemoglobin to form poisonous carboxyhaemoglobin which results in the blood being unable to carry oxygen.