Officers are probing the shooting of tourist Eloise Dixon, from Bromley, south east London, and one man has been arrested, according to reports.
Mrs Dixon was shot by gangsters in Brazil after her husband mistakenly drove their car off the main road and into a favela.
Two police officers who came to her aid said her life was saved by her 13-year-old daughter Isabella, who stemmed the flow of blood with her hand as they waited for help. Four men were hit during the shootout and two died from their injuries.
One of the wounded men was named as Fabricio Wesley Ferreira, also known as WL, and is said to be the drug boss in area.
The other injured criminal identified as Jackson Lima Ferreira, also known as JK, is alleged have been involved in the shooting last Sunday.
Mrs Dixon was hit by two bullets, one passed through her abdomen and the other grazed across her chest, when she was with her husband and three daughters in search for water.
The police operation took place in the Sapinhatuba community, which is seven miles away and some 14 minutes drive from the Agua Santa favela.
Police reported the operation seized 120 packets of marijuana, one kilo of crack cocaine, two 9mm guns with ammunition, one 40mm gun with bullets, a two-way communication radio walkie talkie, two small precision weighing scales and a vehicle which had been tampered with and cloned.
Ferreira, known in the area as the drug kingpin, is linked to the assault against the tourists but not accused of the shooting.
Both wounded bandits have been taken to a local hospital and remain under police guard.
According to A Voz da Cidade, an Agra dos Reis news agency, teams of police were deployed at six yesterday morning.
The battalions split up and invaded various communities including Sapinhatuba, Camorim Grande, Moreno do Moreno and Agua Santa where the Mrs Dixon was shot.