Lincolnshire Police said it is investigating after intruders are believed to have broken in through a bedroom window of their flat in Skegness, Lincolnshire sometime between 10 January and 12 January.
Mr Battersby, 60, is believed to have suffered a fatal heart attack shortly after the pair were last seen alive at their home on Boxing Day, leaving the toddler alone in the dark with no food or water for days.
On 9 January, the two-year-old was found dead next to his father’s body, with preliminary tests reportedly finding that Bronson, who was under children’s services care, had died of dehydration and starvation.
Their landlady Maria Clifton-Plaice said the intruders broke in and stole Mr Battersby’s wallet and medication a mere 24 hours later.
She told MailOnline: “They [the burglars] got in via a back window. They prised open the window, bent the hinges back, and crawled through.
“The television wasn't taken or any other valuable items, but I noticed a few things out of place in the kitchen.
“I looked in the cupboard where Kenny would keep a wallet with his rent money in and it had gone. Whoever had taken it had also taken his Tramadol medication. They'd left the packaging but the pills themselves had vanished. I knew they'd been there the day before when the police were here.
“It was just a day after Kenny and Bronson had been found dead in the living room. It makes you despair really, how low can people stoop?”
Lincolnshire Police said: “At around 12pm we received a report of a burglary at Prince Alfred Avenue on Friday, 12 January. The incident took place sometime between the 10 January and the 12 January. The offenders are thought to have used a bedroom window to gain entry. Our investigations are ongoing. If you have information which could help us, call 101 and quote the number 24000024117.”
The council told The Independent that social services spoke with Battersby on 27 December to organise a visit to the home on 2 January. After receiving no response that day, the council said the social worker contacted police and made an unannounced visit two days later, after which they again contacted police.
However, it was another five days before the father and son’s bodies were found on 9 January, after a social worker gained access from Ms Clifton-Plaice.
Ms Clifton-Plaice told the Mirror: “The police didn't go in first, it was me with two female social workers, and I found Kenny's body, not knowing that his son was lying dead too behind him. It was a horrible tragedy and we are devastated. I cannot tell you how horrible it was. I never expected to find Kenny and Bronson like that. I don't think I will ever get over it.”
The Independent Office for Police Conduct (IOPC) confirmed on Thursday that it is launching an independent investigation “to consider the police response” and “whether there were any missed opportunities” by officers before the deaths.
Lincolnshire Police also said the exact actions of all organisations involved will be analysed in a forthcoming review, while Lincolnshire County Council said it has launched a “rapid review” of the case.
The council confirmed the social worker who tried to visit Battersby and Bronson has not been suspended, but has taken time off following their “traumatic experience”.
Heather Sandy, executive director for children’s services at Lincolnshire County Council, said: “This was a tragic incident, and we are supporting the family at this difficult time.
“We are currently carrying out a review of the case alongside partner agencies to better understand the circumstances, and we await the results of the coroner’s investigations as well.
“Our thoughts are with the family and friends of those involved.”