In an interview from his jail cell with The Associated Press, Mohamed D'Ali Carvalho Santos said: "I don't remember much, I had used too much drugs."
Santos did not say whether he killed her during the brief interview. Police say Santos has already admitted to killing Burke because she threatened to tell the suspect's parents he was a drug dealer and addicted to cocaine.
Authourities said Friday they are looking for another suspect who helped Santos get rid of Burke's head and other body parts.
Santos, 20, was arrested and charged with homicide Thursday after "he confessed he cut her up and even photographed the body on his cellular phone," Goias state police inspector Jorge Moreira da Silva said.
One photo appeared to have been taken in a bathroom shower stall, showing Burke's severed head placed on the chest of her torso along with a bloody butcher knife.
After fatally stabbing Burke on Saturday, Santos left her body in the bathroom and went to a party, returning to dismember her the next day, the police inspector said.
Burke's family in England identified her from a tattoo that said "Mum" after images of the body were broadcast on TV, Silva said.
Burke met Santos in London, where his mother lives, Silva said. She had been in Brazil for about three months.