CHICAGO (Reuters) - An Illinois lawmaker on Monday introduced a bill to ban the forcible removal of travelers from flights by state or local government employees after a United Airlines passenger was dragged from an aircraft last week.

Community members protest the treatment of Dr. David Dao at O'Hare International Airport in Chicago. REUTERS/Kamil Krzaczynski

The Airline Passenger Protection Act, sponsored by Republican state Representative Peter Breen, came after Dr. David Dao, 69, was pulled from a United flight at Chicago’s O’Hare International Airport to make space for four crew members.

The treatment of Dao sparked international outrage, as well as multiple apologies from the carrier, and raised questions about the overbooking policies of airlines.

Under Breen’s measure, passengers could not be removed from flights unless they were presenting a danger to themselves or others, an emergency was taking place or the passenger had caused a serious disturbance, according to a copy of the bill introduced in the state capital, Springfield.

“A commercial airline that removes validly seated customers without serious cause breaches the sacred trust between passengers and their airlines,” the bill said.

The legislation would also bar the state of Illinois from making travel arrangements, doing business with or having investments in any commercial airline that maintained a policy of removing paying passengers to make room for employees traveling on non-revenue tickets.

Dao, who was traveling to Louisville, Kentucky, on April 9, suffered a broken nose, a concussion and lost two teeth when he was pulled from his seat by officers from the Chicago Department of Aviation to make room for four employees on the overbooked flight.

The three officers, who have not been named, were put on paid leave last week, the department said.

“The treatment of the passenger in last week’s incident at O’Hare is inexcusable and must be stopped,” Breen said in a statement. “It reflected badly on the airline, the City of Chicago, and the State of Illinois.”

United Chief Executive Oscar Munoz on Monday again apologized for the incident. [nL1N1HP1HM]

United said on Friday it was changing its policy on booking its flight crews onto its own planes. The company did not immediately respond to a request for comment on the Illinois bill.

Lawyers for Dao have moved to preserve evidence from the flight, filing a motion to keep surveillance videos and other materials related to United Flight 3411 in preparation for a possible lawsuit.

The city and United agreed to preserve the evidence, Dao’s attorney said on Saturday.