NEW YORK — A day after City Comptroller and mayoral candidate Scott Stringer was accused of groping and harassing a woman in 2001, Mayor Bill de Blasio says there should be an investigation into the incident.

In his daily briefing with reporters, de Blasio said that investigation should be swift and immediate, noting the mayoral primary is just weeks away.

“There needs to be an investigation, clearly,” the mayor said. “It needs to be a fast investigation, because the people of this city deserve to know before they make their decision on the future on June 22. We need the facts.”

It’s unclear how any investigation would be conducted considering the incident in question occurred two decades ago. The mayor suggested either the state attorney general or the city’s Department of Investigation could look into it.

On Wednesday, Jean Kim, a lobbyist, accused Stringer of groping and harassing her while she worked as an intern on his unsuccessful 2001 campaign for Public Advocate. Stringer has categorically denied the claim, saying he and Kim had an off and on-again consensual relationship.

The news this week has upended the mayor’s race with the accusation against Stringer slowing any growth he may have been making in the race.