By Robert Plummer
BBC News Online Americas analyst
Ironic as it may now seem, Lino Oviedo originally rose to prominence in Paraguay as an upholder of democratic values.
Lino Oviedo is the most controversial figure in Paraguayan politics
As an army officer in February 1989, he played a prominent part in the uprising that overthrew the regime of Gen Alfredo Stroessner and set the country on the path back to civilian government.
However, he went on to jeopardise that fragile democracy in April 1996, when he disobeyed a presidential order to step down as commander of the army.
The order was issued by Juan Carlos Wasmosy, the country's first elected leader since the 1950s, and Gen Oviedo's defiance seemed like the prelude to a full-scale army revolt.
The rebellion was only defused when President Wasmosy promised Gen Oviedo the defence ministry post if he resigned his command, which he did.
Mr Wasmosy then promptly changed his mind, leaving the now ex-general out in the cold - or so he thought.
Mr Oviedo set up his own faction within the governing Colorado Party and rapidly became its most popular politician.
Even then, many people were tempted to have fun at Mr Oviedo's expense.
His short stature had earned him the nickname of "the bonsai horseman", and during political rallies, he would speak in a mixture of Paraguay's two official languages, Spanish and Guarani, plus a generous helping of German.
Cynical observers said he made little sense in any of them, but the Paraguayan people clearly thought otherwise, and Mr Oviedo easily won the right to become the Colorados' candidate for the 1998 presidential elections.
As the ex-general's poll ratings soared, Mr Wasmosy intensified efforts to bring him to justice in connection with the coup attempt, and he ended up serving a 10-year jail sentence.
Since the electorate could not vote for Mr Oviedo, they did the next best thing and chose his close ally, Raul Cubas, who assumed the presidency in August 1998 and immediately issued a decree freeing the ex-general.
The resulting political power struggle culminated in the murder of Luis Maria Argana, who was a bitter political rival of the Cubas-Oviedo faction despite being vice-president.
In the wake of public revulsion at that dramatic event, Mr Oviedo sought asylum outside the country - first in Argentina, then in Brazil.
But he continued to cast a long shadow over Paraguayan politics, to the extent that his supporters staged another coup attempt in May 2000.
Mr Oviedo denied any involvement in the uprising, portraying the allegations as just another attempt to persecute him.
Lino Oviedo denied being behind the 2000 coup attempt
Despite the Paraguayan authorities' efforts to seek his extradition, Mr Oviedo won the right to stay in Brazil in December 2001, when the Supreme Court in Brasilia ruled that Paraguay's case against him was "politically motivated".
A return to his homeland now means that the ex-general risks being tried in connection with Vice-President Argana's assassination, as well as being sent back to jail to serve out the sentence he received for the events of 1996.
But Mr Oviedo has never given up his presidential ambitions - and with his own Unace political movement at his disposal, he hopes to be able to win the right to contest Paraguay's next election in 2008.