A smuggling scandal involving members of President Tsai Ing-wen’s security detail has rattled Taiwan’s national security establishment. The scandal has led to the resignation of the National Security Bureau’s head as well as the demotion of the president’s chief aide-de-camp.

But one lawmaker says that this is not enough. He says that Taiwanese carrier China Airlines is also complicit.

A cigarette-smuggling operation busted on Monday has led to the arrest of two National Security Bureau agents. But NPP lawmaker Huang Kuo-chang says he believes the agents were not acting alone.

The scandal broke Monday upon President Tsai Ing-wen’s return from a state visit to the Caribbean. Security agents were caught attempting to use rapid customs clearance procedures for members of Tsai’s entourage to bring cigarettes into Taiwan illegally. Customs officials acting on a tip-off seized over 9000 cartons from official vehicles at the airport.

The cigarettes had been ordered through Taiwan’s China Airlines and stored in the warehouse of a catering firm affiliated with the airline. In a press conference, NPP lawmaker Huang Kuo-chang alleged that higher-ups knew about the smuggling attempt, and that someone at China Airlines also helped the operation. Huang is calling for the airline’s chairman to step down.

On Wednesday, Transportation Minister Lin Chia-lung has launched an investigation after the airline failed to deliver a report on the incident.