Former Chicago and Boston marathon champion Rita Jeptoo will know on Thursday if her appeal case launched at the Council of Arbitration for Sport (CAS) to overturn a four-year ban for doping will be upheld.

On Monday, Jeptoo joined her former managers Doctor Rosa and his son Federico in Nairobi for questioning by the Criminal Investigation Department (CID). Though there was no official communication, the trio spent better part of the day at the police department.

"It is a routine call. We have not arrested them. We just wanted to interrogate them and see what information are they willing to give on the subject," a police source said Monday in Nairobi.

Jeptoo, winner of the Boston and Chicago Marathons in 2013 and 2014, was given a two-year suspension by Athletics Kenya after producing positive drug test results for the performance-enhancing drug, Erythropoietin (EPO).

The World Anti-Doping Agency expanded that minimum suspension to four years as of Jan. 1, a decision Jeptoo has challenged at the Council of Arbitration for Sport.

Jeptoo's ban was backdated to October 30, 2014. She produced a positive "A" test sample in September, a result that was announced on October 31.

Several other athletes under the Rosa & Associati Sports Management company have been caught with positive dope tests including is 2014 world 4x800 silver medallist Agatha Jeruto and Mathew Kisorio, a marathon runner. Kenya has over 40 athletes testing positive to doping in the last three years alone.

The interrogation of Rosa and his son comes two weeks after world 1,500m champion Genzebe Dibaba's coach Jama Aden was arrested in Spain.

World 1,500m champion Asbel Kiprop, who is primed to claim gold at the Rio Olympics for Kenya, is one of the elite athletes who have maintained faith in the Italian management camp. New York marathon champion Stanley Biwott is also in their camp.