Venezuela's opposition leader fired a top aide on Thursday after a video surfaced showing the deputy accepting a purported bribe in a scandal that has injected new controversy into the heated presidential campaign.

Henrique Capriles, who has vowed to root out Venezuela's long-rampant corruption if elected, expelled lawmaker Juan Carlos Caldera from his campaign saying the politician had apparently used the candidate's name for financial gain.

State television released a grainy subtitled video that shows Caldera sitting across from a man who asks him to set up a meeting with Capriles. Caldera promises to look into it, adding that a meeting outside Venezuela would be less risky. The man, unseen on camera, hands Caldera two stacks of bills that the lawmaker stashes into a manila envelope.

"Given the information that we have, he's out of the project," Capriles said in a press conference in Caracas. "My grandma used to tell me that the most important thing is our good name. That's why I've always been an open book and I won't allow anyone to get privileges for personal benefit."

Government officials allied with President Hugo Chavez linked the scandal directly to Capriles and demanded an investigation into his campaign finances.

Lawmaker Julio Chavez said a serious probe is necessary to leave no doubt that the money, "doesn't come from drug trafficking, paramilitaries or organized crime."

Justice Minister Tareck El Aissami wrote on his Twitter account: "New faces, old vices...Now Capriles 'it wasn't me' doesn't know anything about it...(hash)Majunche corrupter." Majunche is Venezuelan slang for low quality.

In a news conference, Caldera said the 40-year-old Capriles is not tied to the case. He said the money was for his own election campaign in the Sucre municipality and that the video is a dirty trick by pro-Chavez lawmakers ahead of the Oct. 7 vote. He identified the man in the video as Luis Pena, an aide to Wilmer Ruperti, a wealthy shipping tycoon.

Ruperti has been linked to Chavez since he came out to support him during an oil strike in 2002-2003. He recently gave the socialist leader a gift of two gold-plated pistols once owned by South American independence leader Simon Bolivar. Chavez exalts the 19th century "Liberator" in daily speeches as the spiritual father of his self-styled revolution.

"A group of government deputies staged this show, where I supposedly received a bribe... but they're not saying what it is for. If they're concerned about the truth, why don't they say who's the person with me (in the video)," Caldera said.

"All of this was done with the intention to stain the candidacy of Henrique Capriles."

Caldera said he met Pena after meeting Ruperti in his apartment located in a wealthy Caracas neighborhood. After a friendly chat, the business tycoon asked him to help him meet Chavez' rival. At that moment Caldera said, the millionaire wanted to get close to Capriles because "businessmen can smell who will win."

The political party Primero Justicia, or Justice First, announced Caldera's "separation" from the party on Thursday until the case is solved.

In the run-up to the biggest challenge in Chavez's almost 14 years in office, both sides have stepped up their verbal attacks and tensions have been running high.

Violence broke out at an opposition campaign event in Venezuela on Wednesday in the coastal town of Puerto Cabello after supporters of Chavez blocked a road and a campaign truck was torched. Both sides hurled rocks, and police said at least 14 people were hurt.