The daughter of a Melbourne teacher who was found drugged and bashed to death has issued a heartbreaking update just days after four of her family members were charged over the brutal murder plot.

Sunil Sharma, 66, suddenly disappeared during a visit to India's north last month to oversee renovations at his investment properties in Punjab. 

Indian police now believe the Diamond Valley College mathematics teacher was murdered by his brother over an estimated $AUD740,000 property dispute.

His brother Satish 'Sunny' Sharma was arrested and charged with murder, and his sister-in-law and nephew have been charged over an alleged cover-up.

While Mr Sharma's remains are yet to be recovered, police allege he was spiked with sleeping pills before being bludgeoned to death with a baseball bat.

Police allege his body was then dumped in a canal over an hour away from where he was last seen in Amritsar.

Just days after news of their arrest broke, Mr Sharma's heartbroken daughter Surbhi slammed her relatives in an emotional social media post. 

'I want to say clearly: do not associate my dad with the actions of his "brother." My dad supported his brother and his family financially and emotionally throughout his whole life and raised him like a son,' Ms Sharma said.

'Dad was a good man and a victim of an unthinkable betrayal that still cannot be comprehended by our own family.

'A part of us has been lost to a heinous crime that should never have happened. I pray that the justice system in India enforces the maximum penalty for everyone involved in this calculated and premeditated crime. My dad deserves nothing less.'

Ms Sharma said she has received 'overwhelming support' from the Diamond Valley College community, who have installed a tribute to the teacher at the school.

'There is real comfort in knowing that his soul would be at peace seeing just how deeply loved and respected he is by this community,' she said.

'To everyone who commented about my dad as a maths teacher, he would have loved to see that. It means everything to know he gave the gift of education and shaped the lives of hundreds of students.'

Police also shared new details about Mr Sharma's final hours. 

Senior Superintendent of Police (SSP) in Amritsar, Kanwalpreet Singh, accused Mr Sharma's brother of killing him 'out of greed' and committing fraud.

'When they took the victim from his house, they gave him sleeping pills. After administering the pills, they struck him on the head with a baseball bat, causing a head injury and killing him,' Supt Singh told a press conference. 

'Afterwards, his son was present there and his wife also came. They tried to get rid of evidence. Satish Sharma, out of greed for money, prepared a forged power of attorney. Using that power of attorney, they made deals to sell a house.'

The fourth person arrested was a property dealer with local police stating they are searching for two other people believed to be involved.