"However, the reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases," the team wrote.
Two of the gases, one CFC and the HCFC, are still accumulating.
Previously, seven types of CFC and six of HCFC were known to contribute to ozone destruction.
CFCs, the main cause of the hole in the ozone layer over Antarctica, are man-made organic compounds made of carbon, chlorine and fluorine.
They were phased out from 1989, followed by a total ban in 2010.
HCFCs, CFC-like compounds which also include one or more hydrogen atoms, are less ozone-damaging but contribute to climate change by trapping more of the Sun's heat in the atmosphere.
The ozone layer comprises triple-atom oxygen molecules that are spread thinly in the stratosphere.
It plays a vital role in protecting life by filtering out ultraviolet rays that can damage vegetation and cause skin cancer.
In high latitudes in the Southern Hemisphere, where the ozone layer is damaged or subject to seasonal fluctuations, people are advised to cover exposed skin and wear sunglasses.
Possible sources for the new gases include chemicals used for insecticide production and solvents for cleaning electronic components, said the researchers.
Concentration differences between the samples suggested the dominant source was in the industrialised Northern Hemisphere, they added.
Study co-author Johannes Laube from the University of East Anglia's School of Environmental Sciences said the ozone layer stopped thinning from the late 1990s and there were signs of it starting to recover.
"As many ODSs [ozone-depleting substances], and especially CFCs, take a long time to break down once released into the atmosphere, it will be many decades until it will fully recover," he told AFP.
"Provided we do not have further unpleasant surprises." Martyn Chipperfield, a professor of atmospheric chemistry at the University of Leeds in northern England, said the low concentrations of the four gases "do not present concern at the moment."
But, he added, "the fact that these gases are in the atmosphere and some are increasing needs investigation."
Environment-pollution-ozone AFP
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