Zimbabwean Prime Minister Morgan Tsvangirai has announced he has divorced his wife of 12 days, citing a "greater and thicker plot" by state agents and the media.

Tsvangirai released statements late yesterday saying his marriage to 39-year-old Lorcadia Karimatsenga had been "irretrievably damaged to a point where marriage is now inconceivable".

Tsvangirai, 59, was referring to the traditional wedding he had with Karimatsenga on November 18.

"I was well-meaning and had good intentions to rebuild my family and start a new lease of life following the tragic passing on of my [first] wife. But since the day [I married], everything has been played in the press and I have become an innocent bystander.

"I have become a spectator and things are happening too fast, on camera and without my knowledge. This has led me to conclude that there is a greater and thicker plot around this issue, which has undermined my confidence in this relationship," he said.

Since the announcement of the marriage, state and social media have been stalking Karimatsenga. Mainstream media have reported that Karimatsenga was already expecting twins.

Tsvangirai said the woman had claimed to be pregnant, leading to the marriage. But out-of-wedlock pregnancy carries a stigma in Zimbabwean culture.

Earlier in the day, President Robert Mugabe appealed to the media to respect his coalition partner's private life.

"Everyone has a right to do what he wishes. But this one [Tsvangirai] is being targeted and mobbed by the media every day. Please leave him alone," said Mugabe to journalists.

Tsvangirai's first wife, Susan, died in 2009 in a car accident, which Tsvangirai survived.