Metro officials denied a request Friday by KHTS AM-1220 to obtain a report on alleged illegal blocking activity by Allvision in response to a controversial city of Santa Clarita billboard deal.

County Supervisor Michael Antonovich asked Metro’s Office of Inspector General to look into accusations Allvision — a major beneficiary of the city-county partnership — was paying people to illegally stop signature-gatherers.

The signature-gatherers were paid by a billboard lobbying group to collect signups for a referendum effort resulting in Measure S.

Related: Santa Clarita Referendum On Metro-Allvision Billboard Deal Faces Deadline

The city approved a deal with Metro over billboard removal and construction, and opponents, supported by the California State Outdoor Advertising Association, began a campaign to stop the deal.

The city and supporters claim the deal will remove billboard blight throughout the city in favor of revenue-generating freeway-adjacent electronic billboards, while opponents criticized the terms and the way outreach for the deal was conducted.

The referendum effort was joined by Santa Clarita residents, who brought concerns to Antonovich about the blocking activity — a violation of Election Code 18620, which states it’s illegal to interfere with the signature-gathering process for a legal referendum effort.

Related: County Certifies Signatures For Santa Clarita Billboard Referendum

The petition drive collected the signatures within the legally required 30 days of the start of their effort.

Antonovich requested a look into the claims, which included photographs of men and women interfering with the signature-gatherers, but there was little publicly reported.

Allvision received a cease-and-desist letter in April shortly before three men were arrested on a trespassing charge, after a store manager made a citizen’s arrest against them. A Sheriff’s Station report identifies the men as “blockers,” men and women hired to stop the referendum effort.

The Inspector General’s report cleared Metro officials of any wrongdoing, according to the OIG, which is considered an independent, investigative entity.

The only information released stated: “We found that Metro had no involvement with any matters involving the petition signature gathering activities, and no Metro funds were used related to such activities. Furthermore, no persons complained or notified Metro of any effort to oppose petition signature gathering activities until public comments were made at the Regular Board Meeting on April 24, 2014. Upon being apprised of this activity, Metro staff immediately contacted Allvision (electronic billboard contractor) and requested that they cease involvement in any activity that disrupts petition gathering.”

A request for the supporting documents and emails regarding the report was denied by Metro officials, citing the an OIG exemption to the California Public Records Act.

“With regard to your request for communications and any further information not included in the public report, PUC Section 130625 states: ‘Confidential information, particularly investigative reports for the inspector general, shall not be disseminated beyond the authorized recipient of the report,’” according to the denial from Metro.

Santa Clarita City Council members voted 3-1 to OK a deal with Metro and its partner Allvision, only for it to make the Nov. 4 ballot because more than 13,000 Santa Clarita voters signed a referendum effort to block the deal.

The billboard ballot measure essentially echoes the deal Santa Clarita City Council members approved — it takes down 42 billboards in the Metro right of way throughout the city in exchange for the construction of three new two-sided electronic billboards on freeway adjacent land.

The city created a website with information about Measure S, containing both arguments for and against the ballot measure.