Venezuelan President Hugo Chavez is not in a coma and is responding well to cancer treatment in Cuba, his brother has said.

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

He added that his sibling was "responding well to his medical care".

Chavez, 58, has not been seen in public for a month, and his scheduled inauguration last Thursday turned into a mass rally, with thousands of people joining regional leaders in a show of support for the fiery leftist president.

Chavez underwent cancer surgery in the Cuban capital Havana on December 11, the fourth such operation in the 18 months since his condition was made public.

The rumours were stoked when Chavez did not send a message to Thursday's pro-government rally, the day he was supposed to be sworn in. Unlike past trips to Cuba for medical treatment, no images have been released of him.

The saga has enormous stakes for Venezuela, a nation of 29 million people with the world's largest oil reserves, as well as for the wider region. Cuba and a handful of other leftist-ruled nations depend on Chavez's economic aid.

'Inappropriate' to talk

Peruvian and Argentine Presidents Ollanta Humala and Cristina Fernandez, both friends of Chavez, visited Cuba this week. There was no sign either of them saw him.

Finishing her visit on Saturday, Fernandez said it was "inappropriate" for her to talk about Chavez's condition, which was a matter for his family. "I ask you to show a lot of respect and solidarity," she told reporters in Havana.

Adan Chavez, a physicist by profession who has been a political mentor to his brother and is viewed by Venezuelans as a hard-liner, said foreign media were in league with local opposition activists to promote lies about the president.

"We know this is part of a dirty war by the necrophilic opposition," he was quoted as saying in the news release. "We are sure that with the support of God, science and the people, our president will triumph in this new battle."

Venezuela's opposition leaders are furious at what they see as a Cuban-inspired manipulation of the constitution by Maduro and other top "Chavista" figures aimed at preventing the naming of a caretaker president due to Chavez's absence.

Should Chavez die or have to step down, a new election would be called and would likely pit Maduro against opposition leader Henrique Capriles, the 40-year-old governor of Miranda state, who lost to Chavez in last year's presidential election.

Source: Agencies