I was looking at the IOI 2020 results today and I noticed something strange about the scores of a particular contestant, namely, Ana Paula De Sousa Martin. She was unable to get any points on Day 1, but she then came back and solved two problems completely, performing even better than some silver medalists on Day 2.
Fighter. has not performed very well in the last few IOIs. In her best IOI, she scored 25 points. This year represents a tenfold score improvement! The contest took place online this year, so chances for cheating were higher. Honestly, I find this performance very suspicious.
EDIT: Sadly, this contestant was disqualified.