The IAAF scrapped the 4x400-metre relay world record set by the United States in 1998 because of Antonio Pettigrew's admission of doping.

Michael Johnson, Tyree Washington and Jerome Young were also on the team that set the record of 2 minutes, 54.20 seconds in Uniondale, New York, on 22 July, 1998.

"The IAAF is sending a clear message that we will not tolerate doping," Lamine Diack, the president of track's governing body, said yesterday.

The previous world record of 2:54.29 was set by the American team of Andrew Valmon, Quincy Watts, Butch Reynolds and Johnson at the 1993 world championships in Stuttgart, Germany.

Pettigrew admitted in court in May that he had used performance-enhancing drugs, and USA Track & Field chief executive officer Doug Logan said last month he wanted the record erased as a national mark because it was tainted.

Pettigrew admitted to using performance-enhancing drugs dating to 1997. As a result, the US Anti-Doping Agency has invalidated all of Pettigrew's marks since that date.

"Clearly, we support that move (by the IAAF)," USATF director of communications Jill Geer said. "Certainly the IAAF action sends a strong message."

Geer also said that there won't be a decision until December about erasing the mark as an American record.

Young has also been in trouble for doping. He was eligible in 1998 but was banned for life for a second doping violation in 2004. Earlier this year, after Young admitted to more doping, USADA invalidated his results to 1 January, 1999.