The Boston Globe filed a public records lawsuit Friday against the city of Boston, alleging that Mayor Martin J. Walsh’s administration is improperly withholding public documents related to a widespread federal investigation into the activities of local unions.

Filed in Suffolk Superior Court, the civil suit asks for an order to compel Boston to fulfill a Globe public records request for subpoenas served on the city by the US attorney’s office and for any materials provided to federal investigators in response.

The lawsuit is the latest volley in a back-and-forth over the documents, waged amid an ongoing federal probe into whether unions strong-armed businesses into hiring union workers.

The Globe contends in its suit that since “recipients of grand jury subpoenas are under no obligation of grand jury secrecy,’’ the city cannot meet the legal burden required to deny public access to the documents.

The Walsh administration said it remains “perplexed by the Boston Globe’s actions,’’ and suggested the newspaper had not exhausted its appeals to the state supervisor of records.

“The Globe is seeking federal documents from the city, ignoring the state’s established appeal process and refusing to submit their document request to the federal government,’’ said the city’s chief communications officer, Laura Oggeri, in a statement Friday afternoon.

In general, federal prosecutors are bound by grand jury secrecy rules that do not apply to recipients of grand jury subpoenas. Prosecutors, however, often request that recipients not disclose that they have been served. Globe lawyer Jonathan M. Albano said the newspaper does not need to appeal again to the supervisor of records before seeking a court order.

In its original April 1 request under that state’s public records law, the Globe asked the Walsh administration for:

¦ All subpoenas, memos, letters, requests for records or interviews, and other documents from the US attorney’s office served on the City of Boston since Jan. 6, 2014, the day Walsh took office.

¦ All documents, recordings, e-mails, text messages and other materials provided to the US attorney’s office since Jan. 6, 2014.

The city rejected the request April 11, without confirming whether or not it had received federal subpoenas, saying, “if the city were to receive a subpoena from law enforcement,’’ the authorities would want the city to keep the documents confidential.

The Globe appealed the denial to the state supervisor of records, Shawn A. Williams, who ruled April 22 that the city had failed to meet the legal burden for withholding records from the public, and ordered the city to acknowledge within 10 days if it had received any federal subpoenas.

“The response must contain a statement as to whether the city possesses any responsive documents,’’ Williams wrote. “If the city maintains that any portion of the responsive records are exempt from disclosure it must, within 10 days provide . . . a written explanation, with specificity, how a particular exemption applies to each record.’’

At the end of that time span, however, the city affirmed its rejection of the Globe’s record request and again refused to acknowledge whether the city had received federal subpoenas or shared information with investigators.

“The city maintains that such disclosure could interfere with an ongoing investigation and is simply unwilling to take that risk,’’ the administration wrote. The administration also argued that it must weigh its duty to provide public records “against the competing duty to the public to cooperate with law enforcement by maintaining the secrecy of the grand jury.’’ Producing any records sought by investigators would “alert the public to the nature of an investigation,’’ the city argued. And the administration said it cannot be specific about how any documents sought by a grand jury subpoena are exempt from the public records law, because “the grand jury proceeding is secret.’’

Meanwhile, on April 24, the Globe reported that Walsh had been drawn into a federal investigation into actions of local unions, which brought scrutiny to Walsh’s time as a labor leader.

Mark Arsenault can be reached at mark.arsenault@globe.com.