A drop in price of Lindt chocolate was announced by Countdown on the same day as an inquest resumes into the Sydney Lindt Cafe siege. Lindt Cafe staff members prepare chocolate in the newly reopened cafe.

Supermarket giant Countdown has cut the price of Lindt chocolate on the same day a coroner's inquest into the Sydney Lindt Cafe siege resumes.

Cafe manager Tori Johnson, 34, and lawyer Katrina Dawson, 38, lost their lives during the 17-hour siege, which began when gunman Man Haron Monis entered the Lindt cafe in Martin Place on the morning of December 15, 2014, and took 18 people hostage.

Central Sydney went into lockdown as police treated the siege as a possible terrorist attack.

In what appears to be an unfortunate coincidence, Countdown in New Zealand announced 100g Lindt blocks would be part of its "price lockdown" programme.

The Lindt item sells for $3.50 from Monday - the same day survivors started recounting their harrowing hostage experiences to help unravel the ordeal.

"We would never seek to align our promotional activities with the events witnessed in Sydney. Any suggestion that we have, we would regard as totally offensive to our business and staff," a Countdown spokeswoman said.

"Months of preparation goes into deciding which consumer products go into our Price Lockdown programme and when. As such, the timing of this promotion and the re-start of the inquest into the Sydney siege is purely coincidental."

Monday's hearing is essentially the second instalment in the coroner's inquest into the Martin Place siege. The first hearing was held in January where details of the final moments of the 17-hour ordeal emerged for the first time, including the execution-style killing of Tori Johnson, which forced police to storm the cafe.

Lindt is now cheaper than other similar chocolate blocks sold at the supermarket, with Kiwi brand Whittaker's new Artisan Collection and Belgian chocolate company Guylian's priced at $3.99 per 100g block.

A new Lindt cafe in Sydney's CBD opened in March, three months after the siege. A plaque inside the cafe commemorates Johnson and Dawson, who died along with gunman Monis.

Clarification: An earlier version of this story stated that Monday was the first day of the inquest.