The National Highway Traffic Safety Administration announced Thursday that they are expanding their investigation into reports of carbon monoxide leaks in Ford sports utility vehicles.

The agency said they are expanding their investigation of model year 2011-2017 Ford Explorer SUVs based on a total of 791 complaints, which is up from the initial 154 complaints they began investigating a year ago.

In a statement, Ford said "Safety is our top priority. A dedicated Ford team is working with police customers, police equipment installers, Police Advisory Board members and NHTSA to investigate reported issues and solve them. Customers with concerns about Explorers and Police Interceptor Utilities can call our dedicated hotline at 888-260-5575 or visit their local Ford dealership."

According to NHTSA's report, "To date, no substantive data or actual evidence (such as a carboxyhemoglobin measurement) has been obtained supporting a claim that any of the alleged injury or crash allegations were the result of carbon monoxide poisoning, the alleged hazard. ODI has obtained preliminary testing that suggests, however, that CO levels may be elevated in certain driving scenarios, although the significance and effect of those levels remains under evaluation as part of the EA.”

The possible carbon monoxide exposure in the SUVs has been an ongoing issue for the Austin Police Department. City officials are currently considering removing 400 SUVs from the police department fleet.

60 APD interceptors were reported to be contaminated with the poisonous gas in the past four months.

A representative from Ford previously told KVUE the company takes the safety of their customers very seriously and are cooperating with the federal investigation.

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