Venezuela's Hugo Chavez appeared on state TV on Tuesday, squashing a report he had secretly flown to Cuba for urgent cancer treatment ahead of a presidential election in October.

Strolling around the site of the proposed Veneminsk truck and tractor factory in his home state of Barinas, the 57-year-old socialist leader chatted with workers and looked to be in reasonable health.

I came to Barinas last night to rest, to greet the family. I decided to come and make an inspection (of Veneminsk), he said, wearing a dark blue jacket over a trademark red T-shirt.

His information minister had earlier denounced the rumour that Chavez was back in Havana as part of a dirty war by scum, launched by the opposition ahead of the October 7 election.

It was the latest in a cycle of rumours about the health of the president that have ranged from him having only months to live, to the whole saga being a pre-vote invention by his allies to let him make a Messiah-like return.

A prominent opposition-leaning Venezuelan journalist, Nelson Bocaranda, had written on Monday that Chavez, who had surgery in Havana last June to remove a tumour from his pelvis, had returned to Cuba and that some of his relatives were flying there too.

The president has insisted he is completely recovered, although medical experts say it is too soon to make such a call.

His health is the wildcard in the run-up to the election, when he will seek a new six-year term. The opposition is newly united behind one candidate - Henrique Capriles - and see the vote as their best chance to end Chavez's 13 years in power.

Recent opinion polls have given Chavez an edge over Capriles, thanks partly to a huge program of new state spending on social projects. But about a third of Venezuelans remain undecided, and competition for their votes will be intense.

One medical source close to the team treating Chavez in Venezuela said he had been suffering a tumour lysis, or cell breakdown, which carried symptoms including a high fever.

Before Chavez's reappearance on Tuesday, Venezuelan analyst Diego Moya-Ocampos had suggested his absence could well be a strategy by Chavez's campaign team to put the focus back on him and not Capriles, who since winning the opposition primary had been at the centre of media and political attention.

He said the fact that the latest rumours had spread so fast just underlined the anxiety among supporters each time Chavez vanished from view for more than a couple of days.

(Additional reporting by Marianna Parraga; Editing by Jackie Frank and Vicki Allen)