UPDATE: Later Thursday, Mayor Paul TenHaken's office approved a separate request for defaults and notice letters sent to Village River Group outline compliance issues that led to the termination of the Village on the River project.

Mayor Paul TenHaken’s administration is refusing to release documents related to a downtown parking ramp project that is mired in controversy following the city’s decision to cut ties with a private developer.

Taxpayers are on the hook for as much as $21 million on the parking ramp, which was slated to be the foundation for a 15-floor private development that included hotels, restaurants and other commercial space known as Village on the River.

On Tuesday the city announced that it had terminated its agreement with Village River Group, the private developer, after the city alleged that Village River Group was in default of its agreement, an allegation the developer disputes.

Earlier this year, and unbeknownst to the public, Village River Group asked the city to modify the project.

The Argus Leader requested a copy of those changes earlier this month, but TenHaken’s deputy chief of staff, T.J. Nelson, notified the Argus Leader on Thursday that the records were being withheld. The denial of the request cited four exemptions in state law that allow government entities to keep records secret from the public, including correspondence.

The city is also refusing to disclose the date on which it received Village River Group’s request to modify the project.

The Argus Leader also requested documents related to any financial incentives that Village River Group applied for, as well as any financial incentives or tax breaks offered by the city.

More:Timeline: 5 years of failure in Sioux Falls' downtown parking ramp pursuit

The city is not releasing those documents either.

The city did release an updated development agreement, dated Jan. 5, 2018. The agreement differed from the one approved a month earlier by the City Council in that one of the guarantors for the project, Aaron Hultgren, was removed and replaced by Jeff Lamont, who heads Lamont Cos., an Aberdeen-based company that develops hotels.

Late Thursday afternoon, TenHaken took to social media to say his commitment is to ensuring taxpayers are protected.

"My priority, as always, remains doing what is best for our city. Thank you for trusting your city leadership," he wrote. ‬

The city sold $18.5 million in bonds last April to finance the parking garage. The facility is far more costly than a stand-alone parking garage because it is engineered to be the core of a 15-floor building.

The bonds are backed by the city's second-penny sales tax, but officials have said they want to use revenues generated from the city's parking facilities to pay off the bonds. The bonds are scheduled to be paid off until 2032.

More:Former Mayor Mike Huether distances himself from failure of Village on the River project

Village River Group denies it is in default and says the city cut off communication in the weeks leading up to the contract termination.

When it announced the termination of its deal with Village River Group, the city said it would move forward with finishing the ramp. Future private development at the site was not ruled out.

Sioux Falls City Attorney Stacy Kooistra issued a statement late Thursday defending the city's cautious approach to sharing information regarding the contract termination.

"The public should in no way confuse the protection of information under such circumstances with apathy, a lack of diligence or a lack of transparency," Kooistra said. "To the contrary, a lack of response can be the hallmark of subordinating individual interests to those of the city."

Read the city attorney's full statement below: