The timing of Washington Post's latest "fact-check" on Sen. Tim Scott, R-S.C., which has been panned by critics, is raising questions. 

Scott, who was chosen Thursday to deliver the Republican Party’s response to President Biden's speech to a joint session of Congress on April 28, was the subject of a lengthy piece by the Post’s fact-checker, Glenn Kessler.

The piece, "Tim Scott often talks about his grandfather and cotton. There’s more to that tale," examined the "origin stories" of comments the Senator has made about being an ancestor of slaves. Scott has said his grandfather dropped out of elementary school to pick cotton, so the liberal newspaper enlisted its fact-checker to get to the bottom of the claim.

WASHINGTON POST CRUSHED FOR 'FACT CHECK' ON WHETHER SEN. TIM SCOTT TRULY WENT 'FROM COTTON TO CONGRESS'

Kessler's report was published at 3 AM, roughly 12 hours after Scott was tapped to make the GOP rebuttal against the Democratic president.

Critics slammed the fact-check as a "hit piece" against the up-and-coming Republican lawmaker that ultimately did not debunk his past claims about his ancestry. 

FILE - In this June 17, 2020, file photo, Sen. Tim Scott, R-S.C., accompanied by Republican senators speaks at a news conference on Capitol Hill in Washington. State Rep. Krystle Matthews, a Democratic state lawmaker is mounting a bid to unseat Scott. Matthews told The Associated Press that she will try to register 150,000 new voters across South Carolina to tighten the margin Democrats have struggled to close in statewide elections. (AP Photo/Andrew Harnik, File)

FILE - In this June 17, 2020, file photo, Sen. Tim Scott, R-S.C., accompanied by Republican senators speaks at a news conference on Capitol Hill in Washington. State Rep. Krystle Matthews, a Democratic state lawmaker is mounting a bid to unseat Scott. Matthews told The Associated Press that she will try to register 150,000 new voters across South Carolina to tighten the margin Democrats have struggled to close in statewide elections. (AP Photo/Andrew Harnik, File)

Fox News sent multiple inquiries to Kessler about the timeline of his reporting and the timing of the published fact-check, which were forwarded to the Post's public relations team. 

SEN. TIM SCOTT TO DELIVER GOP RESPONSE TO BIDEN'S FIRST SPEECH TO CONGRESS

The fact-checker publicly shed some light on the timeline of his reporting while responding to a critic on Twitter, who sarcastically exclaimed it was "pure coincidence" that his report came just after the senator's major announcement.  

"Actually, yes," Kessler wrote. "I first started communicating with [Sen. Scott's] staff about this on March 26."

Additionally, Kessler told NewsBusters, "About a week ago, I told [Sen. Scott's staff] I was getting to point of writing a final version and really wanted to talk to him because the goal was to publish sometime in the next week. On Thursday morning, they informed him he was too busy. The story was moved to copy desk before it was announced he would provide the GOP response."

A spokesperson for The Washington Post told Fox News, "The Fact Checker began research on this story several weeks ago. As with all Post reporting, we publish when stories are ready."

The Post did not immediately respond to Fox News' inquiry when asking if the fact-check wasn't "ready" until 3 AM Friday morning. 

CLICK HERE FOR THE FOX NEWS APP

Regarding the fierce backlash the report received, the paper stood by the fact-check, telling Fox News, "The Fact Checker piece acknowledges that Sen. Tim Scott may not have known his full family history and that historical records regarding the lives of Black Americans are often scant. Nonetheless, our reporting adds information found in official records to Scott’s public remarks and writings about his grandfather. The Fact Checker occasionally delves into the origin stories of politicians, often without reaching a conclusion about their completeness or veracity."

Scott’s office declined comment, saying he was focused on delivering the GOP response to Biden’s first speech to a joint session of Congress.

Fox News' Brian Flood contributed to this report.