Zimbabwean President Robert Mugabe. File picture: Philimon Bulawayo

Harare - Zimbabwean authorities on Thursday denied reports that President Robert Mugabe has extended his annual leave due to ill health.

“The President goes on leave every year in January,” Mugabe's spokesman George Charamba told AFP.

“He is still on leave and how can he be seeking an extension when we have not come to the end of January?”

Charamba also denied reports that the veteran leader was unwell.

“As far as I know, he is well and enjoying his rest.”

Mugabe, who turns 90 next month, has been on his traditional annual leave since early January, making one of his regular visits to Singapore.

The government previously announced that his deputy Joice Mujuru will be acting president until the end of the month.

Last week Mugabe was seen visiting his sister at a local hospital.

Mugabe's health has been the subject of much speculation in recent years, with suggestions that his visits to the Far East are for medical treatment.

In 2011 he said in jest that he had resurrected more times than Jesus Christ, after media reports that he had died on holiday.

His spokesman said then that Mugabe had gone for a review following an eye operation.

A diplomatic cable from 2008, leaked two years ago by whistleblower website WikiLeaks, quoted Mugabe's close ally and former central bank chief Gideon Gono as telling former US ambassador Christopher Dell that Mugabe had been diagnosed with prostate cancer.