South Korean police said on Friday it raided the headquarters of Korean Air Lines Co. Ltd. as part of an investigation into embezzlement and breach of trust.

A police official said it was a probe into allegations that company funds were used to pay for construction work at the home of Korean Air Chairman Cho Yang-ho. But he added that the investigation has not yet determined who the suspects were.

A Korean Air spokesman declined to comment. The firm’s shares extended losses on the news to be down 3 percent as of 0524 GMT.