The Fair Political Practices Commission told news outlets that it is investigating after receiving a complaint from the California Democratic Party.
The party, citing a Los Angeles Times article, alleged Elder failed to properly disclose information, including business income and real estate interests.
Political candidates and elected officials in California file statements of economic interests, also known as Form 700, with the commission.
Elder’s initial filing, which described his source of income as coming through Laurence A. Elder and Associates Inc. for being a talk show host, did not include other details.
An amended form filed last week added a list of sources from which Elder received $10,000 or more. The Epoch Times was listed because Elder is an EpochTV host, as was Penn State University; the Washington City, Texas, Republican Party; Salem Media; and seven other sources.
Elder also provided a statement showing that he owns a 50 percent interest in a Los Angeles home, but does not receive rental income from it.
The Elder campaign did not respond to a request for comment.
“We made a simple mistake and we fixed it as soon as possible. These investigations are very common in the campaign world,” Ying Ma, an Elder campaign spokesperson, told the Los Angeles Times.
The penalty for failing to disclose income is a fine of up to $5,000 per violation.
Elder, 69, is the leading candidate among those jockeying to succeed Newsom if voters decide to recall the governor.
The Sept. 14 recall election sees voters choose “yes” or “no” to recalling the first-term Democrat. They’re also asked to choose from among a list of candidates, with the top vote-getter replacing Newsom if a simple majority recalls him.
Other top Republican candidates include businessman John Cox, former San Diego Mayor Kevin Faulconer, and state Rep. Kevin Kiley. Democrats lack a major candidate.