The Tennis Integrity Unit (TIU) is investigating suspicious betting patterns concerning Alexandr Dolgopolov's meeting with Thiago Monteiro at the Winston-Salem Open on Sunday.
Monteiro, ranked 114th in the world, overcame his Ukrainian opponent 6-3 6-3 in just under an hour in the first round of the ATP 250 hard-court event.
World number 63 Dolgopolov did not manage to create any break-point opportunities as Monteiro won through to a second-round meeting with seventh seed Paolo Lorenzi.
The TIU subsequently released a statement on Monday confirming it was looking into the suspicious patterns.
"The Tennis Integrity Unit (TIU) was made aware of concerns over betting patterns during the match between Alexandr Dolgopolov and Thiago Monteiro at the ATP World Tour event in Winston-Salem, USA yesterday (Sunday, 20 August)," it read.
"As with all match alerts, the TIU will assess, make a judgement and take appropriate action on the information received through its co-operative agreements with betting operators."