The killers buried the bodies in the neighbourhood, the police said.
The main accused in the human sacrifice killings in Kerala that have stunned the nation convinced the couple to do it twice, saying it did not work the first time, a senior police officer has told NDTV, revealing how they would kill their victims first and then mutilate the bodies.
"As far as the behaviour of these accused goes, what we have understood is they will first kill and then mutilate and take them into pieces, dismember them and then bury them," the Police Commissioner of Kochi, CH Nagaraju said.
"[The main accused Muhammad] Shafi convinced the other two accused [Bhagaval Singh and his wife Laila] that the first sacrifice did not lead to much improvement in their financial condition... There were some 'ritualistic problems' in the first incident, so they have to do another one," he said.
Describing the behaviour of the killers as "very, very abnormal", the police officer said the wounds inflicted on the two victims resemble ones on the 75-year-old woman who had been sexually assaulted by Shafi two years ago.
The police chief said the allegations of cannibalism, however, are yet to be proven. "As far as evidence is concerned, it's a case of human sacrifice. And whether there is cannibalism or not, has not yet been proved," Mr Nagaraju said.
"There are totally two incidents with us now at hand... the first incident, which happened during June, is to be said to have some such (cannibalism) background. These are stories which are being spoken about, but there's no concrete evidence for this. We'll have to collect scientific evidence for this," he added.
Separately, sources in the police department told NDTV that the accused confessed to charges of cannibalism, with Shafi having convinced the other two that it would "increase their strength".
Calling it "a very, very gory incident", Commissioner CH Nagaraju said the police had enough evidence to make a "watertight case" on charges of murder, kidnapping, cheating and destruction of evidence. "We are collecting more scientific evidence for that, we'll be doing DNA testing," he added.
"Largely, it is a case of one accused, making the other two accused believe that human sacrifice is good for their financial 'upgradation' as a ritual and the other two accused falling into this trap," Mr Nagaraju said.
He said the incident "in a place like Kerala is very, very abnormal, and it is an aberration". "It's not a widely prevalent practice here. People are very, very educated here," the police officer said.