A lawmaker said he feared for the lives of 12 Brazilian football fans being held in Bolivia over the accidental death of a youth during a Libertadores Cup match last month.
The fans support Corinthians, a Sao Paulo team. A 14-year-old Bolivian was killed by a flare fired by a Brazilian fan during Corinthians' away game against San Jose in the Bolivian town of Oruro.
After the incident Bolivian police detained 12 Corinthians fans.
On his return from Bolivia, where he met Tuesday with the fans in an Oruro jail, Brazilian legislator Ricardo Ferraco said: "I return convinced that they are there as hostages."
"I fear for the lives of these Brazilians," he was quoted as saying by the daily Folha de Sao Paulo Thursday.
The lawmaker, who heads the Senate's foreign relations committee, said the Brazilian detainees were in a "precarious situation" surrounded by murderers and rapists.
He said he would press the Brazilian government to intervene, while Foreign Minister Antonio Patriota is expected to be summoned before Congress in the coming days to provide explanations on the fate of the Brazilians.
If found responsible for the death of the Bolivian youth, the Brazilian fans could face jail sentences of between five and 20 years.
A 17-year-old Corinthians supporter, on his return to Sao Paulo last month, took responsibility for the accidental death during the 1-1 draw in Oruro.
The South American Football Confederation (Conmebol) also ordered Corinthians to play their home Libertadores Cup matches behind closed doors, with no fans in the stands, until further notice.