Mr Masuku is losing weight at an alarming rate and has been diagnosed as suffering from hypertension and diabetes, they say.

The president of the Peoples United Democratic Movement, Pudemo, was arrested in early October for defying his bail conditions following a charge of sedition a year ago.

No date has been set for his trial and there is little prospect of one before about February, according to officials.

Pudemo said Mr Masuku had spent more than a month sleeping on the floor of a crowded jail cell with two old blankets, although he was given a bed and more blankets on Thursday.

Poorly treated

Treasurer-general Zodwa Mkhonta told the BBC they were pushing for an early trial, but admitted his spirits were not good.