Athletics/London Marathon: The unusual elixir Paula Radcliffe used to help fuel her latest run into the record books, taking nearly two minutes off her own world record in yesterday's London Marathon, has been revealed - emu oil.

The Briton produced another astonishing performance when she ran two hours 15 minutes 25 seconds, drawing comparisons with Bob Beamon's famous long jump 35 years ago. It might never have happened had it not been for the ancient remedy, which has been popular with Aborigines for centuries yet is almost unknown outside Australia. The oil is extracted from the gut of the emu and is reputed to have speedy healing powers.

Radcliffe had been rubbing it on wounds sustained little more than a month ago, during a crash with a cyclist on a training run in Albuquerque, New Mexico, which left her with injuries to both shoulders and knees and a dislocated jaw, threatening her participation in the race.

It was her physiotherapist, Gerard Hartmann from Limerick, who suggested she try the treatment recommended to him by Cathy Freeman, Australia's Olympic 400 metres gold medallist. Sonia O'Sullivan, the former world 5,000 metres champion, had recently flown in from Melbourne and had a supply with her.

"If you saw the photographs of the day after Paula's accident you wouldn't have thought she would be here," said Hartmann. "Sonia had emu oil with her and then we got some more flown in. It certainly seemed to aid Paula's recovery."

This is just the latest strange substance reputed to have helped female runners achieve great performances. A few years ago the Chinese runners claimed turtle blood was the reason for their fast times, while Japan's Olympic marathon champion and former world record holder Naoko Takahashi swears by juice from giant hornets. Radcliffe is also a big believer in the powers of another flightless bird, the ostrich, which she eats because it is higher in iron than any other meat.

Certainly, the world must be wondering what is the secret of Radcliffe's success. This latest run into the history books was breathtaking even by the remarkable standards the English runner has set herself during the last year.

In 12 months she has gone from being a runner with a reputation for losing pluckily to being, at 29, arguably the greatest female distance runner ever. The purple patch began when she ran 2:18:56 on her marathon debut in the corresponding London race in 2002, the fastest time ever in a women-only race. She then claimed the absolute world record when she ran 2:17:18 in Chicago in October.

Between those were the Commonwealth Games 5,000 metres and the European Championships 10,000 metres titles. Then she set a world best for 10 kilometres in Puerto Rico.

Here, from the moment the gun fired, the only real question was by how much she would smash the record. When she crossed the line in the shadow of Buckingham Palace she had clipped 1:53 off the time, the biggest improvement for 20 years.

The women's marathon mark has now been broken four times in the last 2½ years and six times in the last five. Radcliffe's domination was illustrated by the fact she finished 4½ minutes clear of the runner-up, Kenya's Catherine Ndereba, her predecessor as world-record holder.

"It was almost Beamonesque - it was that good," said Ray Flynn, the former world-class miler from Longford who is now one of the world's leading agents.

Radcliffe's performance means both current men's and women's marks have been set in London, once not regarded as a quick course. But she has now narrowed the difference between her mark and that of the American Khalid Khannouchi, who ran 2:05:38 here last year, to just 7.8 per cent.

It is so good that in statistical tables used by the International Association of Athletics Federations it is considered to be vastly superior to Florence Griffith Joyner's 100 metres performance - a world record, which is predicted to stand for decades.

"This makes the men's world record look soft," said Hartmann. "This was a quantum leap. Paula has taken this event by the scruff of the neck. She has the capacity to tackle it from the start without fear. The men are not running it as aggressively or preparing for it with the same intensity."

The time would have placed Radcliffe 15th in the men's race, 2½ minutes ahead of the first British male, Bingley's Chris Cariss.

"Paula is progressing all the time but it's a natural progression," said Hartmann. "The difference between her and others is she doesn't break down. She takes care of herself. If you look after nutrition, rest, everything, you don't break down.

"If she's progressing at two per cent per year that's huge."

Radcliffe pulled clear of the field from the start and clocked 5:10 on her first mile, which was - almost to a second - her average pace to the finish in perfect conditions with light winds.

London officials had controversially inserted eight male pacemakers into the women's race, making it a "mixed" field and eligible for world-best marks under standards set by the IAAF. An observer from the world governing body said afterwards that everything was conducted properly and the record would be ratified.

"I don't think they made much difference," said Radcliffe. "We were just running together rather than them pacing me. I had more worries about a cameraman coming too close. It definitely wasn't unfair - I still ran 26.2 miles. Everyone said that London could not be a fast course but I knew from last year it was."

World and Olympic champion Gezahegne Abera of Ethiopia won the men's race by less than a metre in a thrilling five-man sprint for the line.

In one of the best finishes in the event's history, second place went to Stefano Baldini of Italy with Kenya's Joseph Ngolepus in third. Baldini was credited with the same time as Abera - two hours seven minutes 56 seconds - one second ahead of Ngolepus, but well outside a world record.

Abera (24), who won the 2001 world championship marathon by just one second, said: "There were so many athletes around towards the end that it was complicated - but my instinct told me when to go."

Kenya's Paul Tergat, runner-up for the last two years, and Morocco's Abdelkader El Mouaziz, winner in 1999 and 2001, were the other two men in the sprint finish. Tergat finished fourth but El Mouaziz weakened and ended up sixth.