Richard Liu, a Chinese billionaire accused of sexually assaulting a University of Minnesota student in August, will not face charges. 

The office of Hennepin County Attorney Mike Freeman released a statement Friday that it did not find enough evidence to charge Liu of the assault.

A 21-year-old Chinese student at the University alleged that Liu raped her in her Minneapolis apartment after she had dinner with him and about 20 other men.

Liu — the founder of the Chinese online retailer JD.com — was participating in the Carlson School of Management’s China Doctor of Business Administration program. He was arrested in late August by the Minneapolis Police Department and was later released, returning to China shortly afterward. 

“After a thorough investigation by the Minneapolis Police Department sex crimes unit and a meticulous review by four senior, sexual assault prosecutors, it was determined there were profound evidentiary problems which would have made it highly unlikely that any criminal charge could be proven beyond a reasonable doubt,” the statement reads. 

Three months is not an unusual amount of time for the office to investigate a assault case, and was unrelated to Liu’s status as a wealthy businessman, according to the statement.