Reports have speculated that Zimbabwe's first lady, Grace Mugabe, is battling colon cancer and has sought treatment outside Zimbabwe.

Grace returned from an extended stay in Singapore six weeks ago claiming that she had her appendix removed.

She has not made a public appearance since March 8, when she attended the International Women's Day ceremony.

According to Nehanda Radio close family sources said while in Singapore during her annual holiday with husband Robert, Grace had an operation to remove part of the colon affected by cancer.

"The First Lady is suffering from colon cancer. She had an operation while on holiday in Singapore and has gone back there for treatment. About 30cm was removed, but now she is in a bad state, that is why she disappeared from the public spotlight," the station quoted a relative.

News Day reported that acting President Phelekezela Mphoko had to stand in for the Grace last week when he received about $1,5 million worth of clothes and food from South Africa-based non-governmental organisation Gift of the Givers for flood victims.

According to the  Southern Eye, Zanu-PF's Oppah Muchinguri confirmed that the first lady was out of the country and seeking treatment, but did not give further details.

"The first lady is a human being like any other person... There is nothing wrong with her going out of the country for check-ups," Muchinguri was quoted as saying.