A family in Nyayo Estate in Embakasi, Nairobi has been left in shock after their kin died after a long bout of prayer and fasting.

Police are investigating the incident in which Catherine Mutuku Kibara 78, was found dead in her house while lying on her bed long after she had been reported missing.

In a police statement, her relatives told police the woman lived alone and it was unusual for her not to pick up calls.

On Monday, her relatives were forced to break on her door after she failed to pick up calls and her mobile phone went off.

Her lifeless body was found lying on the bed after the door was broken down.

Police who arrived at the scene said they stumbled on a register showing she had been fasting and praying since May 18.

Police suspect she died out of starvation.

Her exact cause of death is unknown and what happened during those three weeks is a mystery because no one saw her after she locked herself in her house.

The officers handling the case said they plan to conduct an autopsy on the body to establish how and why she died.

She may have even been dead for a few days before her family opened the door, police said.

Fasting (going without food and drink for a period of time) is an ancient practice and some people believe it must have existed among believers from the very beginning.

Catholics might give up an item or two, such as sugar or caffeine, for the 40 days of lent leading up to Easter, but most people do not forgo all meals.

Fasting is also found in the Jewish and Islamic faiths.

The most common day of fasting for Jews is Yom Kippur, the day of atonement.

Muslims fast during the day during the month of Ramadhan, but they can eat after sunset.

In the Bible, fasting is used during times of mourning, prayer and to repent. Today, Christians mainly use it to get closer to God.