RIO DE JANEIRO — Homicide investigators said Wednesday that they would charge 10 police officers with torture and murder in the disappearance of an impoverished construction worker from Rocinha, one of Rio de Janeiro’s largest slums, the latest development in a case that has been a festering source of tension here for months.

The disappearance in July of the 42-year-old laborer, Amarildo de Souza, set off street protests against police brutality in Rio, São Paulo and other cities. The protests were part of a broader buildup of anger over crackdowns on demonstrators by Brazilian security forces that have included the use of rubber bullets, tear gas and pepper spray.

Graphic details have emerged about what investigators described as the torture of Mr. de Souza by police officers in Rocinha. The disclosure may feed into the exasperation with Rio’s police forces, even as the city prepares to host the World Cup next year and the Olympics in 2016.

According to the newspaper O Globo, which initially reported on the investigation’s findings on Tuesday night, investigators found that officers had submitted Mr. de Souza to electric shocks and asphyxiation with a plastic bag after he was detained for questioning in a sweep of drug trafficking suspects in Rocinha, a hillside favela, or slum, which overlooks some of Rio’s most exclusive residential districts.