By Neil Silver, PA Sport, Edmonton.

Paula Radcliffe suffered heartbreak in the 10,000 metres once again as she was squeezed out of the medals and into fourth place in the World Championships.

And to add to Radcliffe's agony, there was confusion at the end of the race when the scoreboard in the stadium displayed the result with Radcliffe finishing ahead of Gete Wami in third.

The race was a repeat of last year's Olympic final in Sydney, when the battling Brit came agonisingly close to winning a medal before being edged out of a podium finish and into fourth position.

Radcliffe had made a burst with just over three laps to go, but she could not shake off the Ethiopian trio in the race, and her efforts came undone when she was overtaken at the bell.

The race was won by Derartu Tulu, the Olympic champion, in 31:48.81, with Berhane Adere finishing second.

Radcliffe - who ran a time of 31:50.06 - was pipped for medal on the line in a sprint finish by Olympic silver medallist Wami, as the Ethiopians made it a clean sweep of all three medals.

The scoreboard initially had Radcliffe third, and she looked around for confirmation, but after an anxious wait the scoreboard was amended and confirmed that Radcliffe had indeed finished fourth.

"To put it up on the scoreboard for a few seconds was cruel," said Radcliffe.

Even then, the drama was not over yet. As Radcliffe left the track, she became involved in a row with her husband and coach, Gary Lough, over the tactics she had used.

"Gary thought I should have gone sooner," she said: "Everyone gets caught up in the emotions of the event but maybe that was not the right time for him to tell me. But we are okay."

Lough later said sorry to his wife and cuddled her as she gave interviews to the media, and he said she had accepted his apology.

He said: "Paula is the runner and she makes the decisions, and I have apologised to her."

Radcliffe set herself apart from the rest of the race field by wearing long white socks and her long hair in pigtails.

She settled herself a third of the way into the pack in the early stages of the race and looked comfortable.

The pace quickened in the second half of the race as Wami moved to the front of the pack. But Radcliffe moved up to third place to keep the Ethiopian in her sights, before easing back.

Radcliffe gave the British fans in the crowd a lift when she hit the front with just over three laps to go, but her hopes came undone at the bell.

It was Tulu - who also won this year's London Marathon - who made a burst in the final 400m and held off the challenge of her rivals.

Radcliffe had been hoping to completes a hat-trick of titles, as in the last nine months she has won gold medals on both the road and cross country.

She had desperately wanted to prove wrong the critics who claimed she did not have what was needed to win a world title on the track.

But sadly for British hopes she ran out of steam on the last lap and there was no medal to go with the gold won in these championships by Jonathan Edwards in the triple jump and the bronze for decathlete Dean Macey.

"I am disappointed," said Radcliffe. "I thought I could run a lot faster and I knew I had to try something different. I gave it everything I could have done but I couldn't drop the Ethiopians.

"I hope I am stronger for this experience and I am learning all the time. The Ethiopians ran well and in the end I was not quite good enough.

"My plan for the race had the option for me to go to the front earlier, and maybe I should have, but it didn't feel right.

"It felt right when I did go and I went hard, but I had Tulu clicking my heels. I knew they (the Ethiopians) would run as a team and when I went they gathered behind me.

"I still felt with 200m to go that I might hang on for the bronze, but Wami came back at me and when I tried to go again the line came up too quickly."

Radcliffe promised she would not give up her attempt to win on the track.

She said: "This is definitely not my last 10,000m race in a World Championship. I still think I can beat Tulu on the track and I will keep trying."