The death of Senator McConnell’s sister-in-law is now under criminal investigation nearly one month after her passing, Texas law enforcement officials say. 

Angela Chao died on February 11 after being pulled from a car that had been submerged in a pond on the grounds of a private ranch at Johnson City, Texas. Chao was the sister of Mr. McConnell’s wife, Elaine Chao, who served as secretary of transportation for President Trump and as secretary of labor for president George W. Bush. 

“This incident was not a typical accident,” the Blanco County sheriff wrote in a letter to the Texas attorney general, Ken Paxton. 

“Although the preliminary investigation indicated this was an unfortunate accident, the Sheriff’s Office is still investigating this accident as a criminal matter until they have sufficient evidence to rule out criminal activity,” the letter said.

“Releasing the reports, videos and other information prior to the completion of the investigation would interfere with the investigation and possible prosecution of this matter,” the letter continues. 

The letter was first obtained by CNBC. 

Chao was the chief executive officer of her family’s shipping corporation, the Foremost Group, which was founded by her father, James Chao, in 1964. The late Chao previously served on the board of the Bank of China and as a director of the China State Shipbuilding Corporation.

The ranch where Chao drowned is located about 40 miles from Austin, Texas. According to the Austin American-Statesman, deputies from local law enforcement searched the pond for nearly an hour before extracting Chao from the submerged vehicle. Emergency medical services attempted life-saving efforts for 43 minutes before declaring her dead at the scene. 

“The deputies were in the water standing on what they believed was the vehicle, trying to gain access to the possible victim inside the vehicle,” wrote fire Lieutenant Royce Penshorn in his report for the incident.