Representatives of a major Nevada union that has endorsed Barack Obama were seen allegedly strong-arming a fellow union member into supporting their candidate of choice, the Las Vegas Sun reported late Wednesday.

The Sun reported that two members of the Culinary Workers Union, which has formally backed the Illinois senator in Saturday's caucuses, witnessed two other field organizers aggressively attempting to collect pledge cards for their candidate in the break room of a casino on The Strip.

The two members, who are themselves supporting Hillary Clinton, told the Sun the field organizers demanded another union member sign a pledge card or be banned from participating in the caucuses.

Click here to read the Las Vegas Sun article.

The Clinton campaign reportedly attempted to portray the encounter as part of a broader pattern, but the union member who was allegedly intimidated, Sylvia Antuna, said it may have been a misunderstanding. She said the union reps told her she couldn't participate Saturday if she didn't support Obama, but there were no pledge cards and the reps spoke broken English. The union later claimed that the field organizers were merely trying to tell Antuna she had to switch from being an independent to a Democrat to participate in the caucuses.

Democratic rival John Edwards, who is also campaigning in Nevada, used the incident as a springboard to talk about union member rights in Las Vegas Wednesday.

"I heard some reports tonight about the possibility of there being some intimidation of union members to caucus for a particular candidate," Edwards said. "And I just want to say the reason I have worked so hard in the trenches to strengthen and grow the union movement is so that workers' voices are heard."

The caucuses are already the subject of a federal court case, which is examining Thursday whether they can be held inside nine Las Vegas casinos.

FOX News' Cristina Corbin contributed to this report.