Wednesday 11 May 2016 16:49, UK
Sky sources have learned that UK Anti-Doping is struggling to carry out tests in Russia, where it has been brought in to try to restore confidence in athletics.
Russian athletic teams are currently banned from international competitions, including this summer's Rio Olympics.
The World Anti-Doping Agency will meet on Thursday to review progress in Russia but Sky sources understand UK officials have become increasingly frustrated when trying to test athletes from the country.
In some situations, they have been asked to give 30 days' notice, ruling out the possibility of surprise testing.
There have also been issues over delays to blood samples being sent to laboratories and disputes over payments from Russian authorities to UK Anti-Doping's contractors.
Damian Collins MP, a member of the Culture, Media & Sport Select Committee, said: "What the Russians are doing is they are trying to buy the good name of UK Anti-Doping, so they can say 'well, we worked with UK Anti-Doping and they have resolved our issues', when it is noting of the kind.
"I think UK Anti-Doping have been very alive to these problems from the start and they said, when they appeared before the select committee in the House of the Commons, that they didn't feel they had the scope or the manpower necessary to clean out Russian athletics and to solve all of its problems.
"It sounds like they have been frustrated at every turn, as they have tried to work with the Russians."
British running great Paula Radcliffe, the women's marathon world record holder, said: "This isn't a problem just for Russian athletics.
"At the moment, that is where it stands. The Russian track & field team is, at the moment, not going to the Olympics, and the rest of the Russian teams are.
"But evidence that came out was not acted on in other sports.
"In athletics, Russia is not the only country where there is not 'no-notice testing', so fairness needs to be improved across the board, and it should not just be a focus on Russian athletics.
"But at the same time, if they want to get back in, they know what they have to do.
"First of all, they have to accept that there is a problem, and then actively do something about improving that."
