LOS ANGELES (KABC) -- An off-duty Santa Monica police officer boarded a flight from Los Angeles International Airport and traveled to Taiwan with a handgun in her carry-on bag, prompting an investigation by officials in L.A. and Taipei.Officer Noelle Grant, who had been on her way to Thailand for a family vacation, arrived in Taiwan last week and realized she had inadvertently left the firearm in her bag, a spokesman for the Santa Monica Police Department confirmed on Wednesday.Grant then contacted local airport authorities and made them aware of the situation, according to Santa Monica police Lt. Saul Rodriguez. After being initially detained, Grant was released and has been allowed to travel within Tapei but cannot leave Taiwan until the matter is resolved.U.S. authorities are working to help expedite her release from Taiwan, the lieutenant said, adding that the gun was not a department-issued weapon.In a statement, the Transportation Security Administration acknowledged that the policewoman went through security at LAX with the handgun."TSA has determined standard procedures were not followed and a police officer did in fact pass through the checkpoint with a firearm," the agency said. "TSA expects every employee to follow procedures and holds its workforce appropriately accountable."