University students who test positive for Covid-19 in Lincoln could have been left out of local figures, health bosses said.
The county's director of public health Prof Derek Ward said the issue was with the national test and trace system.
Mr Ward said the system connected to the students' GP, so those who test positive could have their case recorded in their home area.
The city has a total of 730 recorded cases.
According to the Local Democracy Reporting Service, Lincolnshire County Council's public health department is calling for the government to look into the issue.
Prof Ward said he could not know for sure what the margin for error was on data around university students with coronavirus.
"It's causing some challenges, which is why we're working so closely with the university, which has actually got really good data on this," he said.
"They're asking students to tell them directly and that's really helping us to understand what's really going on."
He added that students had "good reasons" to tell the university if they tested positive in order to receive the support packages on offer.
On Wednesday, the University of Lincoln and Bishop Grosseteste University confirmed a combined total of 44 cases.