Thiruvananthapuram: A murder most foul, suspected to be because of a case of infidelity, committed by a Keralite woman in Melbourne, Australia, has shocked families back home in the southern Indian state.

According to reports from Melbourne, Sam Abraham, 33, who hails from Punalur in south Kerala was allegedly poisoned to death by his wife, Sofia Sam, 32, because she was having an affair with an old friend from Kerala, Arun Kamalasanan, 34. Kamalasanan was also living in Melbourne.

The alleged murder happened in October 2015, but police in Melbourne made a breakthrough only this month. The news was covered prominently in Australian media, including the Herald Sun. Reports in the media in Kerala indicated that it was an anonymous call to the Australian police that helped crack the case.

Sofia is believed to have been close to both Abraham and Kamalasanan during their college days in Kerala. Her courtship with Abraham culminated in their marriage, but she is believed to have remained close to Kamalasanan, too.

During the time of their marriage, Abraham was based in the Middle East. It was Sofia who first migrated to Australia and Abraham joined her there. Meanwhile, Kamalasanan also moved to Australia with his wife and child.

Sometime later, however, Kamalasanan sent his family back home to Kerala, and intriguingly, there was a knife attack on Abraham near where his car was parked at a train station. That incident happened a few months before he died of cyanide poisoning. Abraham could see the attacker but could not recognise him.

Initially, Abraham’s relatives had thought he had died from natural causes. According to Australian media reports, it was months of covert investigation that helped detectives unravel the proximity between Sofia and her male friend.

Sofia and Kamalasanan have been presented in an Australian court. Investigators have sought extra time to transcribe phone conversations in Malayalam between the two.