Updated: 4:40 p.m.

Democrats are attacking Missouri GOP Senate hopeful Sarah Steelman after news surfaced Thursday that four years’ worth of key records from her tenure as state treasurer are missing.

Most of the documents — sent emails, schedules and travel information, among other content — are required by state law to be preserved in the state archive.

“Where are the documents? Either Sarah Steelman or the national Republican establishment that is propping up her candidacy need to answer that question,” Matt Canter, spokesman for the Democratic Senatorial Campaign Committee, said in a statement Thursday afternoon. “It’s hypocrisy of the highest degree. Steelman flatters herself as a champion for open records laws and even bragged to the press about the procedures she established to maintain records for the public. Now, we discover that most of these key records are gone.”

Indeed, a spokesman for the state treasurer’s office, which Steelman led from 2004 to 2008, told Politico that the documents are nowhere to be found.

“What we have found is that we do not know how they kept those records because we do not have them,” spokesman Jon Galloway said. “Our team has searched the office for any schedules and public documents and we do not have them.”

The disappearance of the documents means Democratic opposition researchers will have to work a little harder to dig up dirt on Steelman, who is challenging first-term Sen. Claire McCaskill.

The DSCC attacks come as McCaskill struggles to emerge from a rash of negative press regarding her and her husband’s failure to pay more than $300,000 in taxes on an airplane over four years.

Steelman spokeswoman Jennifer Morris didn’t directly address the missing documents in an email to Roll Call.

“Senator McCaskill’s liberal allies are so desperate to change the storyline from Sen. McCaskill’s failure to pay over $300,000 in taxes over four years, they are frantically engaging in gotcha politics to find anything which distracts from the central issue: that Sen. McCaskill has clearly proven she cannot be trusted to safeguard tax dollars,” Morris wrote.