Updated: 7:56 p.m.

Sen. Arlen Specter (R-Pa.) has sent Attorney General nominee Eric Holder a letter expressing concern over Holder’s apparent failure to fully complete a Judiciary Committee questionnaire requested in advance of the nominee’s confirmation hearings.

Holder immediately responded to Specter’s letter, replying in a letter of his own that his search for the information requested by the questionnaire was missing inadvertently. Holder said he would attempt to provide Specter with the missing information, although there appeared to be some disagreement over what Specter was requesting and the initial questionnaire answers Holder provided.

“While I made a good faith effort to fully answer the Committee’s questions in my initial submission, it appears that the process I used to search manually and electronically for relevant material from my three decades in public life was deficient,” Holder wrote in a letter to Specter dated Wednesday.

Specter, the ranking member on the Judiciary Committee, wrote on official committee letterhead to Holder at his current place of employment, Covington & Burling, in Washington, D.C.

A copy of the Wednesday letter was posted Thursday by blogger Erick Erickson on the conservative Web site RedState.com.

“Thank you for providing your questionnaire and assembled materials to the Judiciary Committee. Committee staff reviewed your questionnaire responses and noted a number of apparent omissions,” Specter writes. “In view of these omissions, I respectfully ask that you revisit the questionnaire and supplement your submission as soon as possible, or provide an explanation as to why you believe your submission was truly responsive.”

Specter’s letter cited eight questionnaire items that Holder failed to address, including an opinion piece the attorney general nominee wrote regarding gun-show background checks, testimony from five Congressional hearings, several media interviews and work that Holder did for embattled Illinois Gov. Rod Blagojevich (D) in 2004.

Specter and Senate Republicans have previously expressed concern at the speed at which Senate Democrats were attempting to shepherd Holder through the confirmation process.

In response, Senate Democrats pledged to slow things down.