The brother of Hugo Chavez has denied that the ailing Venezuelan president is in a coma, saying he is responding well to cancer treatment in Cuba and making progress daily.

"Reports that the president is in a coma and that the family is discussing ending life support are totally false," Barinas state Governor Adan Chavez said in a statement on Saturday.

A woman holds a candle during a mass to pray for the recovery of Venezuela's President Hugo Chavez in Havana Jan 12, 2013. [Photo/Agencies]

He "continues to respond well to his medical care and to make daily progress in his recovery".

Chavez, whose OPEC-member nation controls the world's largest proved oil reserves, has been out of the public eye since undergoing surgery in Havana on Dec 11. It was the fourth such operation in the 18 months since his condition was made public.

Previously, Venezuelan Vice-President Nicolas Maduro said Chavez was suffering from a severe pulmonary infection that resulted in a "respiratory insufficiency". That fueled speculation about his prospects for recovery - and his political future.

A recent report in the Spanish newspaper ABC said the Venezuelan president was in an induced coma and on life support.

The uncertainty surrounding Chavez's condition has unsettled Venezuela.

The government postponed the president's scheduled inauguration on Thursday, as it became clear that he could not attend. Authorities say the constitution allows Chavez to take the oath of office at a later time.

But the opposition has objected, calling for a medical board to review the absent leader's health - a demand rejected by the Supreme Court, which said the delayed inauguration was constitutional.

Venezuela's opposition plans to present a case before a regional human rights court to challenge a Supreme Court decision that allowed an indefinite postponement of Chavez's inauguration.