Schools in Los Angeles broke ground back in 2013 when they kicked off a plan to put an iPad in the hands of every one of its 650,000 students. By introducing a curriculum centered around Apple's popular tablet, educators were credited with innovative thinking as well as meeting students where they were.

Nearly two years later, the program isn't just dead — it's a full-fledged scandal. Officially killed late last year, the LA Unified School District this week demanded a refund from Apple and Pearson, the company that designed the iPad-centric curriculum, for the $1.3 billion program. Now the SEC is involved.

See also: Why Chromebooks Are Beating MacBooks

The SEC recently questioned school district officials as part of informal inquiry into whether they properly used bond funds for the beleaguered project.

The program stumbled from the start. Out of the gate, it was rife with budget problems. Students found easy ways to bypass the feeble restrictions on the iPads and surf the web freely. Teachers said they hadn't been properly trained to use the technology.

Questions were raised after emails were disclosed showing former LA Unified Superintendent John Deasy, who launched the program, had been in communication with vendors Apple and Pearson before the contracts were put to bid. The FBI confirmed late last year it was investigating as well.

Lawyers for the nation's second-largest school district and an outside firm met at the SEC's LA office in late March to answer questions about the use of bonds for the iPad project and whether officials had publicly disclosed how the funds would be used.

"They asked us to come in and present to them on the bonds themselves," Thomas Zaccaro, a partner with the firm that presented information along with the district, said in an interview with The Associated Press on Thursday. "All in all, we don't see any issue with the disclosures."

Both SEC and LA Unified officials declined to comment to the Associated Press. The SEC does not routinely confirm or deny the existence of an investigation.

Deasy resigned under pressure in October. In December, FBI agents seized about 20 boxes of records form LA Unified as part of a federal grand jury probe into the iPad program.

On Monday, LA Unified general counsel David Holmquist sent a letter to Apple demanding it stop any further delivery of Pearson software and vowed to seek reimbursement for math and reading materials students have been unable to use. The vast majority of students still can't access Pearson material on their iPads, Holmquist said.

Pearson declined to comment to the AP.

At the SEC meeting on March 31, Zaccaro said he and district officials showed that LA Unified had publicly disclosed bond use for computer hardware and software through investor presentations, presentations to rating agencies and to the public in board and county meetings. He also said because general-obligation bonds are repaid through county tax revenues, there is no connection between how proceeds are used and how they are repaid.

"There was a lot of public disclosure about the use of proceeds," Zaccaro said.

Once hailed as a transformative force in education, the iPad — and tablets in general — have had trouble living up to the promises of the early 2010s. The tablet market in general has shown slowing growth as smartphones have gotten bigger and laptops have gotten smaller.

At the same time, Google Chromebooks — cheap laptops that perform well at singular tasks and can be tightly controlled by administrators — have captured the attention of educators and school officials looking to bring technology into the classroom. Data from IDC shows Chromebooks have surpassed iPads in the education market.

Additional reporting by Mashable