Police in Sussex and Kent counties said calls began coming in at 7:30 a.m. Tuesday from residents concerned about the odor, which was described as a mixture of sweat, garlic and rotten eggs, Radio France Internationale reported Tuesday.
Police said they received 25 calls in less than two hours.
Authorities in Paris said they had earlier received reports of the same stench and it was traced to a chemical factory outside Rouen, about 70 miles west of Paris. The factory is owned by U.S. millionaire Warren Buffet and produces a chemical added to odorless gas so people can detect leaks.
"Its inhalation presents no risks," Paris police said.
They said the chemical leaked from the factory Monday and crews worked overnight to neutralize the leak.