Three people have been arrested and released under investigation in connection with the Nottingham Cattle Market fire.
Six businesses were badly damaged in the huge blaze, which began at around 5.40pm on Sunday evening (November 4) and led to an operation involving more than 100 firefighters.
An investigation led by Nottinghamshire Fire and Rescue Service has since identified the likely cause as a firework, used deliberately.
Notts Police said three people were arrested on suspicion of arson on Tuesday afternoon (November 6).
The two men, aged 18 and 25, and a 25-year-old woman were later released under investigation, pending further enquiries.
Video: Some business owners told Notts TV they lost everything in the fire.
A Notts Police spokesman said earlier in the day: “Early indications suggest the blaze involved fireworks which were set off nearby.”
Video: At its peak 100 firefighters were involved in tackling the blaze.
The fire was brought under control by around midnight on Sunday night but the operation lasted more than 24 hours and involved crews pumping water from the Nottingham canal to fight the blaze.