Miss Moore (19) had a majority of 122 votes over her nearest rival when the polls closed on August 14, but returning officer Kyle Matthews is investigating two complaints from different people about aspects of her campaign.
If the complaints are proved and any breaches deemed serious enough, Miss Moore could be disqualified from the election, or the election could be declared "unsafe" and rerun.
One complaint related to her making a computer available so students attending a party at her flat could vote online, Mr Matthews said yesterday.
The second involved "other issues" which he would not reveal.
Both complaints were lodged before the polls closed, he said.
He was in the process of writing his ruling and expected to release it today or in the next few days.
The ruling was open to appeal by either Miss Moore or the complainants and if appealed would be heard by an independent arbitrator.
Mr Matthews said he was likely to rule that Miss Moore had not breached the rules by providing a computer at her party.
The election rules, which "dated back to the days of paper elections" said candidates could not campaign within 20m of a polling booth.
But since the move to online voting, the definition of a polling booth was debatable, he said.
"Technically, any computer capable of connecting to the Internet can be used to cast a vote.
"But my ruling is going to be that [the term] polling booth should mean the official computers OUSA sets up. My recommendation will also be that OUSA will need to revisit the [20m] rule."
He would not give any hints about his likely ruling on the other complaint.
There were four possible outcomes if the complaints were upheld, he said - disqualifying Miss Moore, ordering a re-election, removing some of her votes, or declaring a rule breach but deciding it was not significant enough to have affected the outcome of the election.
Contacted yesterday, Miss Moore said she was not sure what the second complaint was about, but thought it may have been about whether she included all her campaign spending in her expenses return.
She said she was not too worried about the complaints.
"Everything seems to be under control. It should turn out all right - hopefully."
