GENEVA -- Former Chicago and Boston Marathon winner Rita Jeptoo had her doping ban doubled to four years on Wednesday by the Court of Arbitration for Sport.

In its ruling, the CAS judging panel extended Jeptoo's ban until October 2018 and stripped her of her 2014 win in Boston, plus results, prize and appearance money dating back to April 17, 2014. The Kenyan runner previously lost her 2014 Chicago victory.

Jeptoo had been due to earn a $500,000 bonus for leading the World Marathon Majors series standings for the combined 2013 and 2014 seasons. She won back-to-back Boston and Chicago titles in 2013.

Now 35, Jeptoo tested positive for EPO in a September 2014 sample given during training for the Chicago race.

Last week, Jeptoo spoke of her intention to return to competition once her initial two-year ban expired. But on Wednesday her partner said they were expecting that the punishment might be extended after the IAAF appealed what it felt was a lenient ban imposed by the Kenyan track federation.

"They had said they would add two years and she was aware of that," said Noah Busienei, Jeptoo's partner. "There is no other avenue available to appeal the decision and we shall decide the way forward."

CAS said it upheld the IAAF's appeal to increase Jeptoo's original two-year ban, which was to expire this week. Athletes can be banned for four years over a first offence if there are aggravating circumstances.

"(It) was obvious to the panel that the athlete used EPO as part of a scheme or plan," the panel ruled, citing evidence including her long relationship with the unidentified doctor and "multiple visits to see him" which she hid from her manager and coach.

The "undisputed source" of the red blood cell-boosting hormone was an injection by her doctor, the ruling stated.

Jeptoo was also criticized for "deceptive and obstructive conduct throughout the (CAS) proceedings."

"The athlete provided various differing accounts of the circumstances leading up to the injection and also regarding her relationship with that doctor," the court said in a statement.

Jeptoo is the highest profile of dozens of Kenyan athletes to be banned for doping offences over the last four years. Her case reflects a common issue in Kenya: Doctors providing athletes with banned substances for cash.

Serious problems with Kenya's anti-doping program -- including allegations of corruption among authorities -- led to the country being declared non-compliant by the World Anti-Doping Agency in the run-up to this year's Olympics in Rio de Janeiro.

The IAAF gave the East African nation until the end of the year to sort out its problems or face an international ban like Russia.

A scheduled two-day court hearing for Jeptoo's case in April was postponed and two different lawyers withdrew from representing her. When a hearing in Switzerland was held in July, Jeptoo initially joined by telephone but "opted to leave the hearing during the opening statements," the court said.

The Kenyan track body also pulled out of the proceedings, CAS said.

Although CAS said that Jeptoo hid her EPO use from her coach and manager at the time, Jeptoo's former coach is currently facing criminal charges in Kenya, accused of providing Jeptoo and another athlete with banned substances.

Jeptoo's former manager also faces doping charges, although they relate to him allegedly providing two other athletes, not Jeptoo, with banned substances. Coach Claudio Berardelli and manager Federico Rosa, who are both Italian nationals, deny the charges.

AP Sports Writer Gerald Imray in Somerset West, South Africa, and Associated Press writer Mutwiri Mutuota in Nairobi, Kenya, contributed to this report