New details have emerged on what might have transpired on the night Judy Wanjiku Mwai, 73 and her daughter Catherine Nyaguthii were found murdered.

The mother and daughter's lifeless bodies were found at their South B home by Judy's sister.

A highly placed police source told the Star that Catherine Nyaguthii, 47, could have murdered her own blood mother for as yet undisclosed reasons.

And then she ended her own life.

Possibly by poison, it is speculated, since there were no marks on the daughter's body.

“Police have made great progress on the South B murder incident.

We are following very good leads,” the source said.

A caller is said to have called the police and informed them that he/she had committed murder.

"Nimeua. Sasa kujeni muniue" — I have killed, now come and kill me."

Someone used the elderly woman’s mobile phone to call the police on the toll-free line 112 on September 21.

Detectives said the call was made hours before the bodies were discovered by a relative inside their two separate rooms in the four-bedroom house on Monday.

“What could you make of it if one of the deceased women is the one who called the police and said that she had committed murder?” The police source asked

He declined to elaborate.