LOS ANGELES >> The U.S. attorney’s office subpoenaed the Los Angeles Unified School District for records pertaining to its $1 billion iPad project as part of a federal grand jury probe.

A copy of the subpoena released Tuesday requests all documents related to proposals for the district’s cornerstone technology initiative, which has been plagued with problems since its rollout last year. The requested records include proposal scoring documents, review committee files and employee information, among other materials.

LAUSD general counsel David Holmquist told The Associated Press the district was expecting federal agents to visit and retrieve documents toward the end of the week. Instead FBI agents arrived at district offices on Monday, carting away about 20 boxes worth of records

"We turned over all documents that we think are responsive to the subpoena," Holmquist said.

He said the district has not been provided any information on what federal authorities are investigating.

The district’s Common Core Technology Project aimed to provide 21st century learning devices to all of the district’s 650,000 students, chipping away at the technology divide that often leaves lower-income students at a disadvantage from their more affluent peers.

The program was championed by then-Superintendent John Deasy and approved unanimously by the school board in 2013.

"The idea of providing first-class learning technology to all the kids in the district, not just the kids who could afford it, is certainly a worthy educational goal," said Charles Taylor Kerchner, a professor at Claremont Graduate University. "That worthy goal runs up against problems of organizational feasibility, and it did from the beginning."

Hundreds of students initially given iPads last school year found ways to bypass security installations, downloading games and freely surfing the Web. Teachers complained they were not properly trained to instruct students with the new technology. And questions were raised after emails were disclosed showing Deasy had been in communication with vendors Apple and Pearson before the contracts were put to bid. He resigned under pressure, in part from the iPad troubles, in October.

While it remained unclear exactly what aspect of the iPad project — one of the biggest technological undertakings by an urban district in the U.S. — the FBI was investigating, legal experts and education observers immediately focused on Deasy’s relationship with Apple and Pearson and the use of construction bond proceeds to spend money on a short-term device purchase.

Ariel Neuman, a former federal prosecutor, said the government is likely investigating possible fraud involving the contracts.

"If someone doesn’t disclose a relationship they have with Apple," he said, "those could be material omissions that could lead to a wire or mail fraud case."

Interim Superintendent Ramon Cortines had planned to move forward with equipping an additional 27 schools with learning devices, but said Tuesday he was canceling the contract and starting another. Cortines said he made the decision based on "identified flaws" in the L.A. Unified inspector general’s report on device procurement.

He added that the district would continue with a different contract with Apple to provide iPads and another vendor, Arey Jones, to provide Chromebooks for a new set of exams in the spring aligned to the Common Core, the new academic benchmarks being implemented in California and other states around the nation.

"My intent is that the students attending these schools will receive devices under a new contract at the beginning of the 2015-16 school year," Cortines said.

To date, the district has spent $70 million on the project, purchasing 90,713 devices.

News of the probe immediately drew rebuke from United Teachers Los Angeles, a frequent Deasy critic. Union president Alex Caputo-Pearl said Deasy "cannot escape the tough questions about the ill-fated iPad project. He cannot simply resign and leave a mess for others to clean up."

Deasy did not return a request for comment.

Associated Press writer Brian Melley contributed to this report.