The probe into Saturday’s dark disaster at the 34th Calcutta Book Fair has boiled down to sifting through conflicting meter readings submitted by the organisers of the event and the caretakers of the venue.

The Publishers and Booksellers Guild and the West Bengal Trade Promotion Organisation (WBTPO), which maintains infrastructure at Milon Mela, waved printouts containing different meter readings on Monday to prove each other wrong in front of Nandini Chakraborty, the official entrusted with the probe.

Guild officials said they were armed with a CESC report showing that consumption was 1,008 KVA when the lights went out on Saturday evening. But engineers of the WBTPO came up with a printout showing the meter reading as 1,377 KVA when the transformer tripped.

“The transformer tripped because of excessive load. The transformer’s maximum output is 1,250 KVA but the organisers allowed consumption to rise without bothering about the consequences,” said an engineer.

Guild officials argued that the blackout occurred because the transformer’s output dipped well below its claimed capacity. “If the maximum output of the transformer installed by the WBTPO is 1,250 KVA, why did it trip at a meter reading of 1,008 KVA?” asked Sudhangshu Dey, the guild’s ground convener.

Monday’s joint meeting with probe chairperson Chakraborty, who is the executive director of the West Bengal Industrial Development Corporation, was meant to be a stocktaking exercise as well as an attempt to find ways to plug the holes in infrastructure.

But the meeting ended in a deadlock with each side — including the CESC and contractors — coming up with “independent findings”.

Chakraborty said she intends convening another meeting on Tuesday.

“At the end of the day, we must realise that this is not a fault-finding exercise. The idea is to find out what led to the failure on a day when there were around 1.5 lakh people at the ground and to ensure that it does not happen again,” Chakraborty told Metro. “It’s pointless discussing separate findings. Each of these readings needs to be substantiated,” she added.

Sources said Chakraborty is likely to submit the probe report on Wednesday.