Arsonist Stephen Wilkinson, 60, has now been jailed for five years for causing the blaze, which took 40 firefighters several hours to bring under control.
CCTV released for the first time today showed him entering the area where the fire started.
Fixtures and fittings in the market were damaged and stock was destroyed, with firefighters lives said to have been put at risk by the inferno.
Police say Wilkinson, of Mickleton Close, Redditch, had worked at the market for a number of decades.
He was found guilty by a jury at Birmingham Crown Court of arson with intent to endanger life.
The police said the Judge Kristina Montgomery said that the motive was unclear and the only logical explanation was one of petty revenge'.
Wilkinson was said to be 'genuinely sorry'.
Huge plumes of black smoke could be seen from miles around as the blaze took hold on the afternoon of August 6, 2015.