Fandel was threatened after sending off Poulsen
Denmark had fought back from 3-0 down to make it 3-3 when Herbert Fandel sent off Denmark defender Christian Poulsen.
After a spectator ran towards the referee and was intercepted by Danish players, the official walked off, with a penalty he had awarded left untaken.
Uefa has received reports from Fandel and match delegates and will announce any sanctions on Denmark on Friday.
"That will allow us more time to receive the submission from the Danish association," said a Uefa spokesman.
"It seems fairly likely that they will forfeit the match 3-0. The question is really then what other sanctions may or may not be applied."
The match was in Group F, which is currently led by Northern Ireland.
The fan was infuriated by Fandel's decision to award Sweden an 89th-minute penalty and send off Poulsen after Denmark had rallied from 3-0 down in Copenhagen.
"It was incredibly stupid of me," said the unidentified supporter.
"I want to apologize to Denmark, Sweden and the referee for my inhuman behavior.
"People in Denmark hate me, but I have no feeling yet what the reaction in Sweden is, other than they of course believe I am an idiot."
Poulsen was full of remorse after punching Sweden striker Markus Rosenberg in the stomach in the penalty area.
Christian Poulsen wasn't the only one to blame for the episode but that doesn't excuse what he did
Denmark coach Morten Olsen
"I was involved in a tussle with the Swedish player, who I felt had provoked me twice. I saw red and I hit him," said Poulsen.
"I would like to apologise to my team-mates and the general public. It's the most stupid thing I've ever done.
"Denmark coach Morten Olsen told me afterwards there's no place on this stage for this sort of thing and I have to agree.
606: DEBATE
"It happened at a time when we had pulled back Sweden's lead and were in the driving seat. I can't condone it."
Olsen, who watched the match from the stands after being sent off in the defeat by Spain in March, added: "It was a black day for Danish football.
"I've spoken with the players who caused the affair. Christian Poulsen wasn't the only one to blame for the episode but that doesn't excuse what Christian did."
Parken Stadium 
On Saturday, June 2, referee  abandoned the UEFA Euro 2008 qualification match between Denmark and Sweden. The match, which was being played at  in , was tied 3-3 with one minute to go in regulation time.
Christian Poulsen when he played for . 
Denmark had fought back from a 3 goal deficit to tie the match, when Fandel awarded a penalty kick to Sweden and showed  the red card for a flagrant foul. A Danish fan made his way onto the pitch and attempted to assault the referee, although he was at least partially restrained by Danish players. Sweden will likely be awarded a 3-0 victory by the . This and any other sanctions will be announced on Friday.

The fan, whose identity was protected by the judge at his arraignment, apologized to his countrymen, many of whom see him as a traitor. "People in Denmark hate me, but I have no feeling yet what the reaction in Sweden is, other than they of course believe I am an idiot," said the 29-year-old Dane who claims to have consumed 15 to 20 beers before the incident.