Jeter brings it home to smash 27-year-old 'tainted' world record

As the American sprinter Carmelita Jeter crossed the finish line at the end of the women's 4 x 100m relay last night, she pointed towards the trackside clock in wide-eyed astonishment. This figures on the in-field display were: 40.82. It was a seismic moment not just for London 2012 but for track and field.

The world record in the event had stood for two months short of 27 years – since 15 October 1985. Everyone had assumed it was out of touch, at 41.37sec.

It was, after all, one of the marks in the global record books indelibly stained by the steroid-fuelled doping regime of the old East Germany. It was set by the GDR team of Silke Gladisch, Sabine Reiger, Ingrid Auerswald and Marlies Gohr at the same World Cup meeting in Canberra in which Marita Koch established her untouchable 400m world record, 47.60sec.

All – Koch included – were part of the East German track and field machine that was oiled by state-administered steroid doses. The details were found logged in code in the files of the Stasi, the East German secret police, after the fall of the Berlin Wall.

Jeter and her US colleagues – Tianna Madison, Bianca Knight and Allyson Felix – did not just break the tainted time; they smashed it to smithereens, by 0.55sec, a huge advancement in sprinting terms, where decisive margins are routinely measured in hundredths of a second.

It was the second world record of the track and field programme – following David Rudisha's 800m run on Thursday night – and it was a third medal of the Games for Jeter.

After taking bronze in the 200m final on Wednesday, to add to the silver she won in the 100m, the 32-year-old Los Angelean answered questions at the official press conference about her association with Mark Block, a coach and agent who last year received a 10-year ban for his links to the Balco drugs scandal. "Mark Block is a very close friend of mine," she replied. "I love him dearly."

After playing her part in the busting the East German world record, Jeter said: "There was a cloud hanging over us, with people saying, 'They can't do this' they're going to drop the stick.' But we did it.

"I knew that these girls were going to run their hearts out. I knew all I had to do was bring it home."

Jamaica took the silver and Ukraine picked up the bronze.