Police have launched an investigation into the mysterious death of a employee of the National Health Insurance Fund (NHIF) after she collapsed in the Nairobi Central Business District on Monday.

Mary Lilian Waithera, 46, is reported to have collapsed and died under unclear circumstances she was walking together with her colleagues along Kaunda Street right in the CBD at around 5pm.

This comes after post-mortem conducted on Waithera’s body revealed she had been shot leading to her sudden dead and leaving police to pursue whether she had been assassinated and by whom.

The post-mortem report revealed that she had been shot from a raised angle with the bullet entering her body through her collarbone and coming to a halt in her lungs causing her death.

Her family, however say she had never expressed any fears for her life and they had not noticed anything unusual in the recent day and have now been left with more questions than answers.

Mary Lilian Waithera. PHOTO/COURTESY

Eyewitnesses say Waithera suddenly halted holding her chest as she walked with her colleagues from their NHIF Building office then collapsed making them to conclude she had a heart attack.

She was bundled into an ambulance but was pronounced dead before reaching Nairobi Hospital.

Waithera had worked at the NHIF registry department for more than 15 years and now her family has been forced to start making preparations for her funeral at her rural home in Embu County.