Democratic presidential candidate Bernie Sanders looks down during a rally in Springfield, Ore., on April 28. (Ryan Kang/AP)

The presidential campaign of Bernie Sanders said Friday that it has dropped a four-month-old lawsuit that accused the Democratic National Committee of overreacting to an episode in which Sanders staffers improperly accessed voter data information from Hillary Clinton’s campaign.

The announcement followed the completion of an outside investigation into the breach that found that four Sanders staffers had looked at unauthorized data related to 11 states over the course of an hour on the night of Dec. 16, according to a DNC summary of the findings. The DNC declined to release the study itself by the firm CrowdStrike.

In a statement, the Sanders campaign said the investigation confirmed its contention at the time that no one else in the campaign accessed the Clinton “scoring models” or had knowledge of the activity until well after the incident was over. One Sanders staffer was fired in December.

Upon discovering the breach in December, the DNC blocked all access by the Sanders campaign to the voter database that both campaigns were utilizing. A firewall was supposed to prevent the campaigns from viewing one another’s information, but an error by the DNC allowed the Sanders staffers to temporarily get around it.

The Sanders campaigned filed a lawsuit in federal court accusing the DNC of breach of contract for cutting off access to the voter data in the weeks leading up the Iowa caucuses, arguing that proper procedures had not been followed. The two sides quickly reached an accord that restored Sanders’s access, but the campaign did not withdraw its lawsuit until Friday.

The statement issued by the Sanders’s campaign on Friday served as a reminder of how bitter the episode was at the time. It characterized the DNC disciplinary action as “an impulsive overreaction and at a critical point in the campaign just weeks before the closest Iowa caucus results in history.”

The Sanders campaign statement also accused both the DNC and Clinton campaign of overstating the extent of the breach in December. At the time, DNC Chairman Debbie Wasserman Schultz used the word “steal” to describe what the Sanders campaign had done. A Clinton spokesman accused the Sanders staffers of going “hog wild, downloading as much data as they could.”

In a statement Friday, Luis Miranda, the DNC communications director, said that the CrowdStrike analysis "confirmed that the DNC's initial findings, which were  the basis of the temporary shutdown in December, were accurate."

The investigation found that the four Sanders staffers conducted 25 searches on the Clinton data and exported one statistical summary of a search related to voters in New Hampshire. The Sanders campaign said it has not been able to locate that file and no one with the campaign has ever seen it.

The CrowdStrike investigation found no evidence of unauthorized access of data by Clinton’s campaign or that of former Maryland governor Martin O’Malley, who was still in the race at that point.

While the Sanders campaign said it had withdrawn its lawsuit, it took a parting shot at the DNC, saying the campaign “continues to implore the DNC to address the systemic instability that remains in its voter file system” and that “it is imperative that the DNC make it a top priority to prevent future data security failures in the voter file system, failures that only serve as unnecessary distractions to the democratic process.”

The resolution of the lawsuit comes at a time when Clinton has amassed a formidable lead over Sanders in the race for the nomination. On Friday, Sanders campaigned in Indiana, which holds its Democratic primary on Tuesday. Sanders spoke at a rally in support of workers protesting Carrier plant closings that will result in the loss of jobs to Mexico.