SYDNEY (Reuters) - An Australian man built up a 40,000-volt charge of static electricity in his clothes as he walked, leaving a trail of scorched carpet and molten plastic and forcing firefighters to evacuate a building. Frank Clewer, who was wearing a woolen shirt and a synthetic nylon jacket, was oblivious to the growing electrical current that was building up as his clothes rubbed together. When he walked into a building in the country town of Warrnambool in the southern state of Victoria Thursday, the electrical charge ignited the carpet. "It sounded almost like a firecracker," Clewer told Australian radio Friday. "Within about five minutes, the carpet started to erupt." Employees, unsure of the cause of the mysterious burning smell, telephoned firefighters who evacuated the building. "There were several scorch marks in the carpet, and we could hear a cracking noise -- a bit like a whip -- both inside and outside the building," said fire official Henry Barton. Firefighters cut electricity to the building thinking the burns might have been caused by a power surge. Clewer, who after leaving the building discovered he had scorched a piece of plastic on the floor of his car, returned to seek help from the firefighters. "We tested his clothes with a static electricity field meter and measured a current of 40,000 volts, which is one step shy of spontaneous combustion, where his clothes would have self-ignited," Barton said. "I've been firefighting for over 35 years and I've never come across anything like this," he said. Firefighters took possession of Clewer's jacket and stored it in the courtyard of the fire station, where it continued to give off a strong electrical current. David Gosden, a senior lecturer in electrical engineering at Sydney University, told Reuters that for a static electricity charge to ignite a carpet, conditions had to be perfect. "Static electricity is a similar mechanism to lightning, where you have clouds rubbing together and then a spark generated by very dry air above them," said Gosden.