I’ll upset Thompson if I say that Farah is Britain’s greatest – Coe

The 32-year-old racked up his seventh straight global title when he added the 5,000m crown to his 10,000m triumph at the World Championships in Beijing.

The Briton had already won over both distances at the London Olympics in 2012 and the World Championships in Moscow the following year.

His latest successes at the Bird’s Nest stadium, though, came at the end of a tumultuous year in which he was caught up in the doping allegations surrounding his coach Alberto Salazar.

Salazar has denied all the claims against him, while Farah was accused of no wrongdoing, but Coe accepted it was sadly predictable that his achievements would raise eyebrows, especially given the state of the sport at the moment.

The build-up to the championships was dominated by allegations of widespread doping.

“Mo is a wonderful athlete,” said the incoming president of the International Association of Athletics Federations.

“I have watched his progress from the junior ranks, I’ve stood at the side of tracks when he’s been competing and I’ve awarded him medals when he was a junior athlete.

“This is part of the challenge we have. I remember breaking the world mile record in 1981 and I was dubbed by most people an overnight sensation.

“I had to remind them it had taken me 10 years to get to that position since joining my first athletics club.

“We have to be careful here when we start making assumptions about quality and unpredictable performances.

“Often in the largest part it is down to innate ability, hard work, focus and probably somewhere in the locker about 10 years of road mileage and thousands of tons of steel in the gym and people who have given up a large part of their lives to help you.

“It is sadly slightly the territory we have inherited. I think one of my responsibilities is to move the sport off that territory. We are more than a discussion about test tubes, blood and urine.”

Farah’s unprecedented spell of global domination – he has not lost a major outdoor final since 2011 – has reopened the debate about where he stands in the pantheon of all-time greats of the sport.

Former Olympic medallist Brendan Foster described him as Britain’s “greatest sportsman”.

Coe said: “His progress through the ranks has been spectacular and that’s a good thing. If you look at the medals he has won in major championships and the fact this is now the second time (at a World Championships) that he has successfully doubled up at 5,000m and 10,000m, two particularly arduous events, you would be hard pressed to say that he wasn’t the most successful distance runner in terms of medals.

“But there are other things that you need to throw into the balance – world records, times, speeds, all those sorts of things.

“He is a wonderful athlete, I’ll leave the greatest-ever tag to others. If I conceded that I would lose a lifelong friendship with Daley Thompson.”

Thirty-two-year-old Farah followed up his 10,000m triumph by storming to gold over the shorter distance to rack up his seventh straight global crown.

The slow early pace, set by Farah’s team-mate Tom Farrell at the front early on, played into his hands and he took advantage, unleashing his devastating kick past Kenya’s Caleb Mwangangi Ndiku in the final 150m to cross the line a comfortable winner in 13 minutes 50.38 seconds.

It was Great Britain’s fifth medal of the championships and fourth gold.

“It’s incredible to make history and win so many medals for my country,” said Farah, who joked he might “need to get a bigger house” to keep his expanding collection.

The Kenyans had worked as a team in the 10,000m to try to neutralise Farah’s finishing speed and, although it did not work, it was expected his rivals would try something similar again. Instead the early pace was slow.

Ndiku did at least try to pose a problem for the Briton, moving up a gear in a long bid for home with 800m remaining and finally stretching out the field.

But Farah is the master at fast finishing and he went with the Kenyan before bursting past him as they headed into the home straight for the final time.

Ndiku had no answer and had to dig in to hold on for silver in 13:51.75, while Ethiopia’s Hagos Gebrhiwet took bronze. Farrell ended up 15th.

Farah, who revealed he has been suffering from a sore hamstring, said he never felt in danger.

“I could see he (Ndiku) was going hard rather than smooth, so I was looking at him thinking, ‘this guy is a bit too hard here’. Coming into the straight I thought I had him,” he said.

The Londoner experienced the lowest moment of his career at the Bird’s Nest stadium seven years ago when he failed to make the final of the Olympics.

His emotions on Saturday could not have been in greater contrast.

He said: “Seven years ago I remember Bekele winning everything. And I remember thinking with all those medals he has if he only gave me one. The change in seven years is incredible.

“That seven years hasn’t been easy, it’s been continual and year by year trying to build. If you’d have said to me seven years ago you’d have one medal I would have said okay, but to win as many medals as I have is just incredible.”

Britain’s Shelayna Oskan-Clarke produced her second sub-two minute run in two races, but it was not enough to yield a medal in the 800m as she came home fifth in 1:58.99.

Marina Arzamasova took gold for Belarus in 1:58.03.