Two weeks ago, Ms Mjwahuzi pleaded with President John Magufuli to pardon her son.
The mother of imprisoned Tanzanian journalist Erick Kabendera has died at the age of 80, the family has confirmed.
Ms Verdiana Mjwahuzi died on Tuesday at Amana Hospital in the capital Dar es Salaam, where she has been receiving treatment.
Two weeks ago, Ms Mjwahuzi pleaded with President John Magufuli to pardon her son.
Mr Kabendera, detained since July, has been charged with money laundering, tax evasion and leading organised crime. These offences are not bailable.
At the time of his arrest, Mr Kabendera’s ailing mother was living with him.