Originally Published: 20 JUL 22 11:22 ET

Updated: 20 JUL 22 11:46 ET

By Jason Morris and Sara Murray, CNN

(CNN) -- A New York judge has ordered Rudy Giuliani to testify next month as a witness before the Fulton County, Georgia, grand jury that's investigating Donald Trump's attempts to undermine the 2020 election.

Giuliani, who is Trump's former lawyer, was subpoenaed earlier this month. The order to appear on August 9 came after Giuliani failed to appear at a hearing in New York about blocking the subpoena.

CNN has reached out to Giuliani's attorney for comment.

Several state officials have been subpoenaed and have appeared before the special grand jury as Fulton County District Attorney Fani Willis continues leading the investigation digging into the former President's actions in Georgia. Republican Sen. Lindsey Graham was also subpoenaed earlier this month along with the Trump campaign's other former legal advisers, including John Eastman, Cleta Mitchell, Jenna Ellis and Kenneth Chesebro.

Tuesday, it was revealed that Willis has also informed all 16 of the individuals who signed an "unofficial electoral certificate" that was ultimately sent to the National Archives in late 2020 that they may be indicted in the probe.

Prosecutors may be moving closer to possible criminal charges against those involved in the effort. It also suggests the probe may be drawing closer to Trump himself, as it comes on the heels of subpoenas that were issued to several members of the former President's legal team who took part in overseeing the effort to overturn the election results in Georgia and other key battleground states.

A judge in Georgia initially signed off on Willis' efforts to subpoena Giuliani earlier this month. Because Giuliani is a New York resident, his summons was moved to a court there, where a New York judge scheduled a hearing giving Giuliani an opportunity to quash the summons. When the former Trump lawyer didn't show, the New York judge signed off on the order for Giuliani's testimony.

CNN previously reported that Giuliani is one of a handful of witnesses who were subpoenaed related to their appearance before Georgia state lawmakers in December 2020. During his early December appearance, Giuliani provided testimony, witnesses and so-called evidence that demonstrated voter fraud, according to court filings. Even after those allegations were investigated and disproven, Giuliani "made additional statements, both to the public and in subsequent legislative hearings, claiming widespread voter fraud in Georgia during the November 2020 election," by re-upping the same previously debunked evidence, according to court filings.

This story is has been updated with additional details.