Kansas Secretary of State Kris Kobach (R) is defending using a personal email account to conduct business as the vice chair of a commission convened by President Donald Trump to investigate voter fraud, continuing a trend of shielding his communications from public view.

In a statement provided to ProPublica ― which first reported Kobach’s use of private email ― last Friday, Kobach defended his practice, saying he was serving on the voter fraud probe not in his official capacity as Kansas secretary of state, but as a private citizen. Kobach told ProPublica that using his official email would be a “waste of state resources.”

President Trump launched the Presidential Advisory Commission on Election Integrity in May in order to look into his claims that widespread voter fraud had been committed during the 2016 election.

Kobach, who is running for governor of Kansas, is using that distinction between private citizen and public official to refuse to release commission messages to the public. When the Kansas City Star submitted a public records request for messages related to work on the commission, Kobach’s office denied the request saying “any communications that may exist are not communications in his official capacity as Secretary and thus not public records.”

“Secretary Kobach is serving as Vice Chairman of the Presidential Advisory Commission on Election Integrity in his personal capacity. Commission members are considered ‘Special Government Employees’ under federal law,” Samantha Poetter, a Kobach spokeswoman, said in a statement to HuffPost. “The members of the Commission were never issued federal email accounts, but they received ethics training and were instructed that they could continue to use personal email accounts as long as they ensure that all emails relating to commission business are copied or forwarded to a federal government email account.”

“Because Secretary Kobach is serving on the Commission in his personal capacity, not as a representative of the State of Kansas, he determined that it would be inappropriate to use his Kansas state email account.”

But Kobach’s use of a private email account and his refusal to release messages underscores the extent to which he has gone to block the public from viewing his work on changes to federal voting laws. Experts have warned that Kobach’s use of a private email account could violate federal and state statutes governing disclosure.

Kobach’s use of a private email on Trump’s voter fraud probe comes as the commission faces question about its own transparency. Ahead of its first meeting on July 19, it failed to publicly post all of the documents commissioners would reference at the meeting, a decision a federal judge called “incredible.” Department of Justice lawyers apologized for the failure and conceded the commission had gotten off to a “chaotic start.”

Ezra Rosenberg, co-director of the voting rights project at the Lawyers’ Committee for Civil Rights Under Law, which is suing the commission for failing to disclose documents, said all members of the commission should be issued a government email address.

“We have sued the Commission to insure that all of its documents are disclosed to the public, as required by law. Secretary Kobach cannot hide his communications by using his private email account. This shows why every member of the Commission must be issued a federal email account and that account must be used for all communications concerning the Commission,” Rosenberg said in a statement.

In addition to his work on Trump’s commission, Kobach has come under separate scrutiny for shielding efforts to bring about changes to existing federal voting laws.

In response to a separate lawsuit brought by the ACLU challenging a Kansas law requiring people to prove their citizenship to vote, Kobach has gone to great lengths to urge a federal judge to keep sealed two documents detailing his proposed changes to the National Voter Registration Act (NVRA), a 1993 federal law requiring motor vehicle agencies and some other state agencies to provide opportunities to register to vote. He initially refused to even turn over the documents in the court case, but was eventually forced to do so by a federal judge and got sanctioned for misleading the court about the contents of the documents.

A judge is still considering a request to unseal the documents. One is a memo circulated in his office detailing changes and the other is a document he brought to a meeting with Trump last November. In court filings, Kobach’s lawyers have said the public does not need to see the documents and that making them public would make it more difficult for him to advise Trump.

But one email made public in the litigation showed Kobach using a private email account to email a Trump transition official the day after election day saying he was already working on amendments to NVRA to allow states to impose a proof of citizenship requirement when people register to vote.

Critics seized on that revelation as a reason to question Kobach’s impartiality in helping to lead a national voter fraud commission.

Meanwhile, Kobach’s use of a personal email account is also of heightened interest because of the central role Hillary Clinton’s use of a private email account and server for government business played in the presidential campaign last year. Even though Clinton said she turned over all work-related emails to the State Department, Trump repeatedly criticized her for it and suggested she was hiding something. Vice President Mike Pence, who is the chair of the voter fraud probe, also used a private email account while he was governor of Indiana.