Kansas Secretary of State Kris Kobach speaks during a news conference Tuesday, Feb. 17, 2015, in Topeka.

Topeka ? A computer database system that Kansas Secretary of State Kris Kobach frequently touts as a tool to prevent voter fraud is now the subject of a federal lawsuit and a new academic study that says it is wrong most of the time.

The system, known as Crosscheck, was developed in Kansas in 2005, five years before Kobach was elected. But its use by other states has grown rapidly under Kobach’s administration, and by 2016, 30 states were reported to be using it.

The participating states share their voter registration information with the Crosscheck system, which uses each person’s first name, last name, date of birth, and last four digits of their Social Security number to look for potential duplicates.

The idea is to identify duplicate registrations and prevent people from “double voting” — that is, casting ballots in more than one location. But a new study by researchers from Stanford University, the University of Pennsylvania, Harvard University, Yale Law School and Microsoft Research said Crosscheck’s protocols could result in potentially thousands of legitimate voters being wrongly purged from the voting rolls.

Using Crosscheck information from Iowa in the 2012 presidential election, the researchers said, “We identified more than 2,500 cases in which only the earlier registration record was used to vote in 2012, compared to just 7 instances in which both the earlier and the later registration were used to vote. Thus, such a strategy would eliminate more than 300 registrations used to cast a seemingly legitimate vote for every double vote prevented.”

That study was published Tuesday, Oct. 24. Three days later, on Friday, the Indiana chapter of Common Cause, a nonpartisan government watchdog group, filed a federal lawsuit in Indiana citing that study and seeking an order to block election officials in that state from cancelling voter registrations under the Crosscheck procedures.

The lawsuit challenges a new Indiana law that allows county election officials to purge an apparent duplicate voter registration on the spot, without notice to the voter and without waiting through two federal election cycles, as required by the National Voter Registration Act.

Kobach did not immediately respond to a request for comment Tuesday.

Bryan Caskey, who heads the Elections Division in the Secretary of State’s office, said he had not seen the lawsuit and had not had time to read the study, but he insisted that the Crosscheck system itself is accurate.

Caskey confirmed that Kansas initiated the Crosscheck program, which was initially a joint project with Missouri, Iowa and Nebraska, in 2005. He said Kansas continues to manage the database, but that election officials here only purge voter registrations after confirming the information with the voter or after waiting the required two federal election cycles.