'Probe Mugabe's ability to hold office'

A Zimbabwean lawyer has asked the country's highest court to order an investigation to determine President Robert Mugabe's fitness to hold office, after a series of blunders that prompted speculation about his health.

The papers filed by lawyer Tinomuda Chinoka seek to order the speaker of parliament and the president of the senate to conduct the investigation.

"Having a president that may lack capacity to carry out the job threatens democracy, undermines the constitution and puts in jeopardy the very foundation, security and future of the nation," read the papers filed with the Constitutional Court.

Chinoka listed a number of incidents casting doubt on Mugabe's ability to rule, including his tumble on a red carpet at Harare International Airport in February 2015.

They also referred to a gaffe last year when he read the wrong speech at the opening of parliament.

"Any person with their mental alertness intact would have recognised a speech that they have read only three weeks previously," said the papers.

Mugabe, who turns 92 later this month, has ruled Zimbabwe since independence from Britain in 1980.

His health has been the subject of speculation in recent years.

In January he returned from his annual month-long holiday during which rumours flared that he had collapsed and died in Asia.