US sprint sensation Richardson tests positive for marijuana
The Times cited two unnamed people with knowledge of the test results in reporting the positive test, which was first reported by The Gleaner newspaper in Jamaica.
Richardson's agent, Renaldo Nehemiah, did not respond to an AFP request for comment.
Richardson, 21, won the 100m at the US trials in Oregon in June, punching her ticket to Tokyo in a season in which she became the sixth-fastest woman ever at the distance with a time of 10.72sec at a meeting in Florida in April.
A positive result from a test at the trials would invalidate her victory there and open the door for a lower-placed finisher to gain a berth in Tokyo, even if Richardson receives the minimum punishment.
The Times reported that other athletes in the women's 100m final at the trials had been told they had been moved up in the standings.
While Richardson's camp had not specifically addressed the reports on Thursday, the athlete did post a cryptic tweet, telling followers: "I am human."