The battle over Denver’s Flock camera surveillance system escalated Tuesday with nine Denver City Council members asking the city auditor to step in and essentially block Mayor Mike Johnston’s proposed extension of a contract with Flock.

In a letter dated Oct. 25 and obtained by CBS News Colorado, the nine council members asked Denver City Auditor Tim O’Brien to not sign a five month contract extension with Flock that Johnston announced last week.

“We have serious concerns about Flock Group Inc’s ethics, transparency and credibility,” reads the council letter. “We do not believe the City and County of Denver should continue doing business with a company that has demonstrated such disregard for honesty and accountability.”

The council members accuse Johnston of deliberately evading city council oversight of the Flock agreement by violating city contracting rules.

Last week, the Mayor announced he was unilaterally extending Flock’s camera contract with Denver through early 2026, with measures in place to prevent federal authorities from accessing data from Denver’s Flock cameras.

In response to the city council letter, a spokesperson for Johnston on Tuesday released a statement saying, “It is the Mayor’s job to keep the city safe. License plate readers do just that, and there is nothing about this no-cost extension that is beyond the scope of the Mayor’s responsibilities or authority.”

Auditor Tim O’Brien said on Tuesday he would perform due diligence “by considering whether this contract is intentionally split in violation of city contracting rules and assessing if it subverted City Council’s independent oversight.”

Some city council members have expressed privacy concerns around the use of the cameras.

Denver City Council’s Health and Safety Committee is planning to discuss the Flock issue again on Wednesday with an update scheduled on the Surveillance Task Force.