Republican Georgia Governor Brian Kemp.
CNN  — 

Georgia Republican Gov. Brian Kemp testified for roughly three hours on Tuesday before an Atlanta-area special grand jury probing efforts by former President Donald Trump and his allies to overturn the 2020 election in Georgia.

A judge previously said Kemp, who sailed to reelection last week, would not have to testify until after the midterm elections. Judge Robert McBurney, who oversees the grand jury, rejected Kemp’s earlier efforts to quash his subpoena, but said there would be limits to the questions Kemp could be asked.

Among the topics prosecutors were eager to ask Kemp about was a December 2020 phone call in which Trump allegedly tried to push Kemp to convince state legislators to overturn Joe Biden’s win in the Peach State.

“I am unable to comment further on ongoing grand jury proceedings,” a spokesperson for Kemp said Tuesday.

Kemp is one of a handful of witnesses left to testify in the Fulton County investigation. Will Wooten with the Fulton County District Attorney’s Office said there are “very few” witnesses left and they don’t anticipate this grand jury will go on much longer.

Wooten made the comments during a separate court hearing in Florida where former Trump national security adviser Michael Flynn was fighting his subpoena.

“The likelihood is that this grand jury is not going to be hearing testimony much longer,” Wooten said during the hearing.

On Wednesday, Cassidy Hutchinson, former aide to Trump’s White House chief of staff Mark Meadows, is scheduled to testify in Fulton County, and on Thursday, Sen. Lindsey Graham is slated to appear as a witness before the special grand jury.

Wooten also said that after the special grand jury issues its final report, the district attorney’s office would terminate its existence.

The Georgia probe – set off by an hour-long January 2021 phone call from Trump to Georgia Secretary of State Brad Raffensperger asking him to “find” the votes necessary for Trump to win the Peach State – has steadily expanded with time.

It now covers presentations on unfounded election fraud claims to state lawmakers, the fake electors scheme, efforts by unauthorized individuals to access voting machines in one Georgia county and a campaign of threats and harassment against lower-level election workers.

For months, the special grand jury has been scrutinizing those events to determine whether any of them may have been illegal. When the panel, which does not have the power to issue indictments, completes its work, it is expected to issue a report with recommendations, including whether anyone should face criminal charges.

CNN’s Jake Tapper, Sara Murray and Zachary Cohen contributed to this report