Sen. Roland Burris’ (D) chief of staff, Darrel Thompson, stepped down from his position Friday, the latest hit in a sting of bad news for the embattled junior Senator from Illinois.

“As of today, my role as Interim Chief of Staff to Senator Burris will end,” Thompson said in a statement released Friday afternoon.

Thompson was put on detail from Senate Majority Leader Harry Reid’s (D-Nev.) office to serve as Burris’ interim chief of staff, and he will return to his post with the Majority Leader.

“Though my tenure was relatively brief, I enjoyed and valued my time with Senator Burris, his entire staff and his other advisors,” Thompson said.

A source with knowledge of the situation said Thompson had been kept in the dark about Burris’ decision to file a new affidavit with the Illinois state legislature on Feb. 4, even though Reid announced Thompson’s move on Jan. 30. In the affidavit, which sparked the current controversy, Burris acknowledged that he did not tell lawmakers at an impeachment hearing that he had spoken with several top associates of then-Illinois Gov. Rod Blagojevich (D), despite repeated questioning on the subject.

The source said Thompson did not find out about the affidavit until the Chicago media discovered it on Feb. 13. That was the same evening that the news broke.

Reid spokesman Rodell Mollineau would only provide a short statement: “Sen. Reid appreciates the work Darrel did for Sen. Burris and is happy to have him back.”

Thompson’s resignation is the latest drip in a flood of bad news for Burris, who was appointed in December by Blagojevich — who has since been impeached and removed from office — to fill the seat left vacant by President Barack Obama.

Illinois Gov. Pat Quinn (D) called for Burris to step down in a press conference Friday. Soon after, White House press secretary Robert Gibbs also suggested Burris resign.