IndyCar has filed a breach of contract lawsuit against the organizers of the now-scrapped Boston Grand Prix.

The lawsuit against Boston Grand Prix LLC and two executives was filed Monday in federal court in Indianapolis. The complaint and all exhibits have been filed under seal by IndyCar, which states in court filings that its complaint contains trade secrets, sanction and event fees and sensitive commercial information.

Stephen Starks, IndyCar vice president of Promoter Relations, issued a statement on Tuesday night that the suit was filed "to enforce the organization rights under the agreement with Boston Grand Prix and to cause them to meet their obligation to refund the ticket revenue to IndyCar fans who purchased tickets to the event."

IndyCar entered into an agreement with Boston race organizers in May 2015 for races to be run in the city annually from 2016 through 2020. The promoters announced April 29 the race would not happen, citing potential costs to correct flood zone issues with no guarantee it could get approval in time to stage the Sept. 4 race.

In a news release sent by the promoters' attorneys Edward Colbert and Michael Goldberg, Boston Grand Prix organizers said they have seen the lawsuit.

"Boston Grand Prix disagrees with many of the statements made by IndyCar in the complaint and does not believe that IndyCar has a basis for recovering any funds from the company," the news release said. "In fact, Boston Grand Prix holds substantial claims against IndyCar arising from IndyCar's termination of the Grand Prix event that had been scheduled."

The news release indicated that organizers are working on a new event for 2017 that could help fulfill contracts and generate revenue.

"Countless hours of hard work and financial resources were expended in the effort to bring this exciting event to our city," the news release states. "Currently, BGP is working assiduously to arrange an alternative event to take place in Boston in 2017, which the company believes may be the best way to protect the interests of event sponsors, vendors and ticketholders.

"The company is also exploring ways to marshal its remaining assets to create resources for ticketholder refunds. Those efforts are extensive and continuing."

Watkins Glen International will host an IndyCar race on Sept. 4, 2016, in place of the Boston event.

IndyCar filed a redacted complaint that it expects would become public in 14 days. The complaint would not include sensitive information, such as the amount of insurance the Boston Grand Prix was required to have, as well as sanction agreements and other pricing arrangements. Grand Prix of Boston CEO and president John Casey and former CEO Mark Perrone are also listed as defendants.