Tensions appeared to be rising around the long awaited welterweight world title fight between Manny Pacquiao and Floyd Mayweather, with the fighters' camps reportedly at odds over a proposed doping penalty.

Pacquiao adviser Michael Koncz told the Los Angeles Times on Thursday that he was "a little puzzled and dismayed" that ­Mayweather wouldn't agree to the $5 million penalty ­Pacquiao had proposed should either fighter test positive for a banned drug.

Mayweather Promotions chief executive Leonard Ellerbe, however, told the newspaper that the drug testing protocol for the May 2 fight in Las Vegas had been "rigorously negotiated" by Pacquiao promoters Top Rank.

In comments to espn.com, Ellerbe called Koncz an "idiot."

"If this moron didn't convey his fighter's wishes when the negotiation was going on that's their problem," Ellerbe said. "This is a lame-ass attempt to generate publicity."

Drug testing was an issue in attempts to put a Pacquiao-Mayweather fight together in late 2009 and early 2010.

Mayweather wanted random Olympic-style blood and urine testing, but Pacquiao objected

to some of the protocols and the deal disintegrated.

Mayweather later accused the Filipino ring icon of using performance-enhancing drugs, a charge which Pacquiao denied.

Pacquiao sued Mayweather over the accusation and the two settled out of court.

Drug-testing differences have been just part of the long and winding road to the May 2 match-up between the two fighters widely considered the best pound-for-pound fighters of their generation.

The bout has required rival telecasters Showtime and HBO to work together to produce a fight considered a lock to break all records for pay-per-view viewers and revenue.

Pacquiao, a two-term Congressman from Sarangani province in the Philippines, is 57-5 with two drawn and 38 knockouts while Mayweather is 47-0 with 26 knockouts.