He said other common symptoms are headache, fatigue, sore throat and muscle pain, but he warned that the ZOE app regularly detects 20 distinct signs.
Speaking at Sky News’ Sophie Ridge on Sunday, he said: “We have been saying since last spring that the range of symptoms should be expanded.
“This was made clear by the people who reported our app, where more than 20 Covid symptoms are linked.
“Thirty percent of people with a positive CRP test do not have these three classic symptoms.
“This is particularly true in the first three days of the disease, when it is most infectious.”
Professor Spector said that ignoring the other symptoms represents a “real risk” of missing cases and believes that changing the list would reduce infections by 30 percent.
“I understand why we didn’t do it last spring, because we didn’t have a testing process and that would have crashed the system,” he added.
“But now we have a fantastic test system, which is capable of doing more than 600,000 tests a day. It’s time to do that and add those symptoms.”
A Department of Health spokesman said: “A scientific group of experts keeps Covid-19 symptoms under review while our understanding of the virus continues to evolve.”