The fire destroyed the warehouse in Lutterworth

Fire destroyed the Primark warehouse at Magna Park, Leicestershire, gutting the 440,000 sq ft complex in November.

Leicestershire Fire and Rescue Service said the results were inconclusive after several months of investigation.

Investigator Jim Baker said: "We have tried to imagine what could have set fire to the building - but we have now exhausted all the possibilities."

Sprinkler broken

On the night of the blaze, the sprinkler system was not working properly because of problems with the water supply, investigators discovered.

But Mr Baker praised the company's evacuation plan, which allowed all 130 employees to escape without injury.

He said the fire service had liaised with police forensic experts and assessors from the insurance company throughout the investigation.

The file on the fire will soon be closed and the results sent to the deputy prime minister's office, he said.

Some 15 fire engines from Warwickshire and Leicestershire went to the site, next to the A5, just outside Lutterworth.

Christmas sales

The warehouse, which opened five years ago, was owned and run by logistics company TNT, but was a dedicated unit for Primark.

No-one was injured in the fire.

Primark drafted in replacement stock from the Far East to supply its stores for the Christmas sales.