By Andrew Cawthorne

CARACAS (Reuters) - Venezuelan President Nicolas Maduro has called for legal action against a former government official who now teaches at Harvard University and wrote an opinion piece that contributed to a fall in the nation's bond prices earlier this week.

Ricardo Hausmann, a Venezuelan planning minister in the 1990s, wrote that Venezuela was in arrears across various sectors of the economy and had "defaulted" on its people. "So, should Venezuela default on its foreign bonds?" he asked.

Combined with pessimism on Wall Street over lack of market-friendly reforms, last week's article on Project Syndicate, a web portal that carries opinion pieces on global affairs, hit Venezuelan bond prices. They recovered somewhat, however, when Maduro responded with reassurances the nation would pay every dollar it owed.

However, in a speech late on Thursday, the socialist president accused Hausmann of being a "bandit" and mouthpiece for an international conspiracy against the government.

"I've ordered the public prosecutor, and I've spoken to the attorney general, to start actions because you're involved in a campaign to damage our fatherland," Maduro said. "We have the proof in your declarations and articles, up there in your mansions where you live with money stolen from Venezuela."

Reached by telephone, Hausmann said Maduro's comments were falsehoods that exposed the lack of independence of the judiciary and a desire to find scapegoats for Venezuela's economic mess.

"He is a liar when he says that anybody but himself is destroying the Venezuela economy," he told Reuters.

"I have no financial stakes in this game, no relations with any business groups ... He says he has evidence and the evidence is op-eds. Doesn't the Venezuelan constitution guarantee freedom of speech?"

Maduro, who narrowly won election to replace the late Hugo Chavez last year, often blames capitalist foes for an "economic war" against Venezuela.

Critics say his persistence with failed policies, such as strict currency controls and squeezes on the private sector, are to blame for Venezuela's high inflation, economic slowdown and widespread shortages.

"You are the main adviser, Ricardo Hausmann, of all these groups who want to cause economic damage," Maduro added in Thursday's three-hour speech, the latest of long daily public appearances.

(Editing by Lisa Von Ahn)