UK Athletics performance director Dave Collins has revealed more than 70 British athletes have missed at least one out-of-competition drugs test.
Ohuruogu faces a two-year ban if found guilty of a doping offence
Four of them have missed two - meaning they face a ban if they miss one more.
Christine Ohuruogu was provisionally suspended and withdrawn from the Great Britain team in Gothenburg after missing three tests in 18 months.
"Certainly over 70 have missed at least one test. I think four are on two missed tests," Collins told the BBC.
"They are very aware of the seriousness of the situation and we are working with them," he added on Radio Four's Today programme.
Asked if the four were high-profile athletes, Collins replied, "varying".
As things stand Ohuruogu, the Commonwealth 400m champion, has a "case to answer" after claiming changes to her training schedule led to her missing tests.
I think Christine has been hung out to dry
Former European javelin champion Steve Backley
If she is found guilty of an anti-doping violation by an independent disciplinary committee, she faces the prospect of a two-year suspension.
Britain's former European javelin champion Steve Backley told Radio Five Live he was "not surprised in the slightest" by the number of missed tests.
"It seems as though there is a big administrative mess," he said.
"I think Christine has been hung out to dry as a result of trying to tie up the admin of drug-testing.
"I know from first-hand experience it is tough to know exactly where you are going to be at every point of every day.
"I don't think for one second Christine Ohuruogu has tried to gain an unfair advantage or tried to avoid testing by any means.
"I think she has just been busy preparing for these championships and possibly not been where she thought was going to be on a daily basis.
If every other country in the world was testing as rigorously as us it would be a much cleaner sport
"If that is the case and there is talk of her possibly missing the Olympics in the future, that is an absolute tragedy for Christine."
Backley said athletes should be extra vigilant, though, after missing a test.
"You miss one and there are no alarm bells," he added.
"But you know you have only got three lifelines, so you make sure you don't miss a second. The only surprise is that Christine should miss three."
Athletes have to declare where they will be available for testing one hour, five days a week.
Collins said the issue was "the talk of the championships" among the British team in Gothenburg and Ohuruogu's suspension had "opened a can of worms".
"It's an extremely complicated process but they have to do it," he added. "It's an essential part of them being professional athletes and us making sure it's a drug-free sport.
It's part of your responsibility as an athlete to be where you say you're going to be
"It's not without its challenges and there are certain ways in which we are trying to make this easier for the athletes.
"If every other country in the world was testing as rigorously as us it would be a much cleaner sport."
World Anti-Doping Agency chairman Dick Pound has told athletes to "get organised" to avoid the possibility of missing tests and risking suspension.
"If people go to where you say you're going to be and you're not there that counts as a missed test and if that develops into a pattern the conclusion is that that counts as a positive test," Pound told Five Live Sport.
"You know as a professional athlete that doping controls are a very important part of making your sport fair, not only for you but for everybody else.
"It's part of your responsibility to tell your federation where you are, and to be where you say you're going to be."