Ousted Honduran President Manuel Zelaya says he has returned to his country, almost three months after the coup which overthrew him.
"I am here in Tegucigalpa," he told local TV. Venezuelan President Hugo Chavez also said Mr Zelaya was back.
But de facto Honduran President Roberto Micheletti said Mr Zelaya was "in a hotel suite in Nicaragua".
And a UN spokeswoman denied a report that Mr Zelaya was in its office in Tegucigalpa, reported Efe news agency.
The left-leaning president had been living in exile in Nicaragua since being ousted at gunpoint on 28 June.
The country's de facto rulers, led by Mr Zelaya's former ally Roberto Micheletti, have threatened to arrest him if he returns. "I cannot give details, but I'm here," Mr Zelaya told Channel 36 television by telephone. He said he was "here for the restoration of democracy, to call for dialogue".
Mr Micheletti told a news conference the report of Mr Zelaya's return were "not true".
A UN spokeswoman in Tegucigalpa also denied that Mr Zelaya was in the organisation's buildings.
"We do not know where this information came from but I can say with certainty that it is not true," said Ana Elsy Mendoza.
But crowds of Mr Zelaya's supporters have gathered outside the UN offices in the capital to celebrate his alleged return.
Elisabeth Sierra, a spokeswoman for the Honduran Embassy in Nicaragua, said Mr Zelaya was urging his supporters to go there to "protect the constitutional president of Honduras".
Mr Chavez, speaking on Venezuelan television, said Mr Zelaya had travelled overland for two days to return to Honduras, "risking his life with four companions" to reach the capital.
He appeared to be on the telephone to Mr Zelaya as he was speaking and said the ousted leader had Venezuela's support.
Guatemala's President Alvaro Colom also said Mr Zelaya was in the Tegucigalpa, saying it was "the end of the political crisis" in the country, reported Efe.
The crisis erupted after Mr Zelaya tried to hold a non-binding public consultation to ask people whether they supported moves to change the constitution.
Shortly after the coup, Mr Zelaya attempted to fly back to Honduras, but failed when the authorities blocked the runway at Tegucigalpa airport.
Talks in Costa Rica on resolving the crisis, hosted by the country's President Oscar Arias, broke down without the parties reaching an agreement.
Later that month, Mr Zelaya briefly crossed into Honduras from Nicaragua - a symbolic move the US described as "reckless".