Six doctors from world athletics’ governing body, the IAAF, and officials from the Spanish Anti-Doping Agency were also present to carry out doping controls on some athletes.

The IAAF later released a statement explaining this arrest was the culmination of a long-running investigation.

“The arrest today of distance running coach Jama Aden follows a lengthy investigation by the IAAF which began in 2013, working in close cooperation with Interpol, the Spanish authorities including the Spanish National Anti-Doping Agency [AEPSAD], Spanish police and other organisations,” said the IAAF.

“The IAAF will use all available resources and powers to protect clean athletes and the integrity of our sport. This includes targeting and investigating individuals and coaches who are intent on exploiting athletes and promoting the use of prohibited substances.”

Aden has a proven track record of nurturing some of the best middle-distance runners.

Aside from Dibaba, he has coached two-time world indoor 800m champion Abubaker Kaki Khamis and 2008 Beijing Olympics 800m silver medallist Ismael Ahmed Ismael, both from Sudan, 2012 London Olympics 1,500m champion Taoufik Makhloufi of Algeria, 2012 world junior 1,500m champion Hamza Driouch, a Moroccan-born Qatari, and 2013 world indoor 1,500m champion Ayanleh Souleiman of Djibouti.

But Aden has also courted controversy, with Driouch handed a two-year ban for inconsistencies in his biological passport and French runner Laila Traby also being banned after testing positive for blood-boosting EPO.

Driouch at first claimed Aden had doped him, but later retracted his allegations.

Dibaba, sister of running legend Tirunesh, has seen her pre-Rio Olympic plans hampered by a toe injury that has recently ruled her out of meetings in Eugene, Oslo and Stockholm.

The 25-year-old world record holder is the big favourite to strike gold in the women’s 1,500m at the August 5-21 Rio Games.