LOS ANGELES (AP) — California’s Republican Party on Monday acknowledged owning unofficial ballot drop boxes that state election officials said are illegal.

After receiving reports about the drop boxes in three counties, California's secretary of state issued a memo Sunday telling county registrars these boxes were illegal and that ballots must be mailed or brought to official voting locations.

“In short, providing unauthorized, non-official vote-by-mail ballot drop boxes is prohibited by state law,” the memo said.

On Monday, state GOP spokesman Hector Barajas said that the party owns the boxes and has no plans to remove them. He would not say how many exist or where they are located. Barajas said the state’s law governing so-called ballot harvesting allows an organization to collect and return groups of ballots and that collection boxes provided by a private organization to help people vote are no different.

“Democrats only seem to object to ballot harvesting when someone else does it,” Barajas said.

The controversy surfaced after state election officials received reports of the boxes in Fresno, Los Angeles and Orange counties, all regions with highly competitive U.S. House races. Democrats have blasted the use of the unofficial boxes and say they fear Republicans could use them to gather and dispose of ballots.

In California, ballot harvesting is allowed under certain rules. Election officials said individual voters can ask someone else to turn in a ballot on their behalf but should be careful when doing so.

In Orange County, which is home to 3 million people between Los Angeles and San Diego, a regional field director for the state’s GOP posed in a social media photo with one of the boxes and wearing a face covering supporting the congressional campaign of Michelle Steel, a county supervisor challenging Democratic Rep. Harley Rouda for his seat representing a coastal district. Rouda flipped the seat two years ago from a long-time conservative.

There were reports of similar drop boxes at a church in the Los Angeles County community of Castaic and at various locations in Fresno County in California's farm-rich Central Valley, including party headquarters, a gas station and gun shops.

In Orange County, Registrar of Voters Neal Kelley said said official drop boxes are clearly recognizable and carry official county elections logo. He said it wasn’t clear how many voters had used unofficial boxes but after receiving reports about them, he notified the state and district attorney’s office, which is investigating.

Fresno County Republicans said they will remove the boxes and ballots will be turned in to county election officials, which was always the plan, the Sacramento Bee reported Party Chair Fred Vanderhoof saying.

Democrats criticized use of the boxes and said they want those using them held accountable. Rachel Potucek, a spokeswoman for the Democratic Party of Orange County, said she didn't know what Republicans planned to do with the ballots they collected and worried they could target Democratic areas with boxes to suppress votes.

“Sadly, this is par for the course from the Republican Party — well versed in making it harder, not easier for Californians to vote,” Rusty Hicks, California Democratic Party Chair, said in a statement.