The CPI is based on 18 surveys from 12 independent institutions, which were carried out among local and expatriate business people and country analysts. TI says no country was included in the ranking with results from less than three surveys.

”Latin America is marked by corruption, but there are signs that efforts to fight the problem have had some success,” Arturo del Castillo, director of CIE Consulting & Research, which specialises in the fight against corruption, told IPS.

The Mexican analyst said the wave of accusations against governments and ex-presidents is a demonstration that progress is being made. He added that never before have so many former Latin American presidents faced charges that have either been proven or are under investigation.

The list began to grow in 1992, when a corruption scandal triggered mass protests in Brazil, forcing then president Fernando Collor de Mello to step down, said del Castillo.

Brazil received a CPI score of 3.9.

Topping the list of the accused is current Nicaraguan President Enrique Bolaños. The comptroller-general's office in that Central American country is demanding that he be removed from office because of his resistance to explaining the origin of huge sums of money held in bank accounts that helped finance his campaign in 2001.

Bolaños succeeded Arnoldo Alemán (1997-2002), who was convicted in late 2003 and sentenced to 20 years in prison for money laundering.

A similar problem is faced by Costa Rican President Abel Pacheco, who has been at the centre of an investigation since 2003, also because of supposedly illegal campaign financing.

Costa Rica received a CPI score of 4.9 and neighbouring Nicaragua just 2.7.

Pacheco's predecessor, Miguel Angel Rodríguez (1998-2002), who was appointed head of the Organisation of American States (OAS) on Sep. 15 and was forced to resign from that post less than a month later, is accused of receiving a kickback during his presidential term, in a telecommunications deal involving the French firm Alcatel.

Rodríguez was immediately handcuffed and arrested when he returned to his country after resigning as OAS chief.

Another former president in Costa Rica, Rafael Calderón (1990-1994), is barred from leaving the country until an investigation of his alleged participation in a corruption case involving Social Security funds is completed.

In the case of Bolaños in Nicaragua, the OAS decided to intervene, sending a special mission this week to try to prevent an institutional crisis, because the opposition, which has a majority in Congress, has the power to remove him.

”For the political opposition it is always tempting to cry 'corruption' and mount an attack,” said del Castillo. ”It is important to treat this question with great care, because the idea of fighting corruption should not reach the extreme of putting the institutions into continuous crises, which doesn't help anyone.”

The analyst said the origin of the wave of accusations against former and acting presidents lies in the increased public awareness on the social problems generated by corruption, new anti-corruption laws and international conventions, and the watchdog role that has increasingly been assumed by the media.

In Argentina, which was given a CPI score of just 2.5, former president Carlos Menem (1989-1999) is under prosecution in connection with several cases.

Menem, who already spent several months under house arrest in 2001, now lives in Chile and is facing an international arrest warrant after refusing to testify.

A survey carried out by KPMG, an international audit, tax and advisory firm, among 1,000 business people, university deans, civil society leaders and public employees from all three branches of the state, indicates that corruption levels in Argentina today are the lowest in 20 years.

Another former president who may soon be tried is Gonzalo Sánchez de Lozada in Bolivia, who was forced to resign in October 2003 by a month-long popular revolt triggered by plans to export natural gas to the United States and Mexico under conditions that were opposed by the public.

He is accused of being responsible for the deaths of nearly 70 protesters who were killed after he called the army out to quash the demonstrations. On Oct. 14, parliament authorised the Supreme Court to try the ex-president, who is living in the United States.

Bolivia scored 2.2 on the TI report.

In Chile, the country with the lowest level of corruption in Latin America according to TI, former dictator Augusto Pinochet (1973-1990) is facing charges for illicit enrichment, besides the multiple lawsuits for crimes against humanity. He is under investigation for eight million dollars found in secret bank accounts in the United States.

More former leaders face prosecution for corruption in Ecuador, meanwhile, than in any other country in the region. The Andean nation was given a score of 2.4 by TI.

Abdalá Bucaram, who was impeached and removed from office by Congress in 1997 in the midst of a huge popular uprising, is living in Panama, although the case against him for embezzlement of public funds continues.

Fabián Alarcón, who replaced Bucaram as interim president from 1997 to 1998, is under investigation, and spent six months under arrest in connection with alleged irregularities in hiring public officials.

He was succeeded by Jamil Mahuad (1998-2000), who was toppled by social protests led by the country's well-organised indigenous groups.

Since he was replaced by his vice-president, Gustavo Noboa (2000-2003), Mahuad has been living in the United States. He is still under prosecution for abuse of functions.

Noboa also ended up fleeing the country after he was accused of corrupt handling of public funds. He is living in the Dominican Republic, where he was given political asylum.

Another ex-president in trouble is Alfonso Portillo (2000-2004) in Guatemala, a country that ranked 2.2 on the TI scale.

Portillo settled in Mexico after he was accused of opening several bank accounts with public funds. Prosecutors report that they are preparing to ask for his extradition.

In the Caribbean, former Haitian president Jean Bertrand Aristide, whose term was cut short in February in the midst of looting and violence and U.S. intervention, is accused by opposition groups of corruption and political violence.

Haiti, which scored 1.5, shares the last spot, 145, on TI's global ranking with Bangladesh.

In Paraguay, which scored 1.9, Juan Carlos Wasmosy, who governed from 1993 to 1998, was convicted in April 2002 and sentenced to four years in prison for irregularities. However, he was absolved by an appeals court in September.

Raúl Cubas, who succeeded him until 1999, was also denounced for the misuse of public funds after he was forced to step down by social unrest in the wake of the assassination of vice-president Luis María Argaña and the killings of seven young protesters in March 1999.

Cubas fled to Brazil, but returned to Paraguay in 2002, where he faced prosecution.

Cubas' successor until 2003, Luis González Macchi, is also being tried, for the alleged diversion of 16 million dollars from banks that had gone under.

The list is completed by former presidents of Peru (which scored 3.5) and Venezuela (2.3). Former Peruvian president Alberto Fujimori (1990-2000), who has lived in Japan since he faxed his resignation from that country, is facing an extradition request based on accusations of crimes against humanity and embezzlement of public funds.

Carlos Andrés Pérez, who governed Venezuela from 1974 to 1979 and from 1989 to 1993, was sentenced to house arrest for the misappropriation of public funds.

Del Castillo said this long list of former and current leaders shows that corruption can no longer be hidden so easily in this region.