On Friday, as he forcefully denied an allegation of sexual assault made against him by a former Senate aide, Joseph R. Biden Jr. called on the National Archives to release any complaint related to the accusation.
But the National Archives immediately responded that any such personnel records would not be under its control but would rest with the Senate itself.
Then the Biden campaign sent a letter to the secretary of the Senate asking the office to “direct a search” for any relevant records, if they existed, and make the results of the search public.
On Monday, the secretary of the Senate said that her office had no legal discretion “to disclose any such information.” That prompted Mr. Biden’s personal attorney to respond to the Senate office asking, in effect, what his campaign needed to do to locate any relevant documents and arrange for their release.
The exchanges have thrown into confusion Mr. Biden’s attempt to make public any documents related to the allegation, a level of transparency he promised when he appeared on MSNBC Friday to address the issue for the first time, saying unequivocally that the assault “never happened.” Even the Biden campaign itself appears uncertain of how to proceed.
At issue is an allegation by Tara Reade, who says that Mr. Biden assaulted her in 1993 in a Senate hallway, pushing her up against a wall and penetrating her digitally. Ms. Reade worked as an aide in Mr. Biden’s Senate office in late 1992 and part of 1993.
She has told The New York Times that she filed a complaint with a congressional personnel office but she does not have a copy, and such paperwork has not been located. The complaint, she said, alleges harassment but not an assault.
In a statement released on Monday, the secretary of the Senate said, “Senate Legal Counsel advises that the Secretary has no discretion to disclose any such information as requested in Vice President Biden’s letter of May 1.” The statement cited, in part, “strict confidentiality requirements” of a law governing such records; it did not confirm that there was a complaint.
Shortly afterward, the Biden campaign said that Bob Bauer, Mr. Biden’s personal lawyer, had responded on behalf of Mr. Biden with three questions pertaining to the release of a complaint that included clarifications on any circumstances that would allow the office to release information.
“Is just the existence of any such records subject to the same prohibition on disclosure?” he asked.
In an apparent reference to Ms. Reade, he also asked whether there was “anyone, such as a complainant, to whom such records, if they exist, could be lawfully disclosed?”
And he asked if the Senate could “release the procedures and related materials, including any standard forms or instructions, that the Office of Senate Fair Employment Practices followed in 1993 for the intake and processing of any complaint of this kind?”
On Monday evening, the office of the secretary of the Senate said that it had responded to the questions earlier that day.
The office said it “was advised by Senate Legal Counsel that disclosing the existence of such specific records would amount to a prohibited disclosure under the Government Employee Rights Act of 1991.”
It added, “we are not aware of any exceptions in law authorizing our office to disclose any such records that do exist, if any, even to original participants in a matter.”
The office said it had also sent Mr. Biden’s counsel a public document with the rules governing the Office of Senate Fair Employment Practices.
But Mr. Biden received a boost on Monday when Senator Elizabeth Warren became the latest high-profile Democratic woman to