Police said a fire outside the former Poundland building in Worthing may have started in discarded bedding left behind by a homeless person but said no crime was identified.
Officers attended the scene in Montague Street at 6.50pm yesterday (Sunday, December 16) where firefighters were dealing with a blaze in a derelict shop building, a police spokesman said.
Police said the fire was put out in minutes.
The spokesman said: "It was thought possible it may have started in discarded bedding left behind by a homeless person, but no crime was identified and no one was hurt.
"The building was boarded up to make it secure."
A spokesman for West Sussex Fire and Rescue Service confirmed that two fire engines attended the scene at 6.48pm before leaving at 7.15pm.
There were piles of black ash at the site this morning where it appeared that the bedding had been on fire.