Top Kenyan marathon runner Rita Jeptoo could see her two-year doping ban doubled if the International Association of Athletics Federations gets its way.
The IAAF have lodged an appeal with the Court of Arbitration in Sport (CAS) claiming the ban imposed on Jeptoo in January was too lenient.
For her part, Jeptoo has appealed against the ban and is also lobbying the CAS to be allowed to continue running while the matter is resolved.
Jeptoo, 33, was banned after being caught doping with the banned blood-boosting hormone EPO.
The suspension, imposed by Athletics Kenya's anti-doping commission, was the minimum mandatory punishment under international anti-doping regulations in place when she was caught in an out-of-competition test last year.
However, athletes caught doping after January 1 this year now face a mandatory four-year ban.
On Tuesday, the CAS announced it had received two appeals over the matter.
"In her appeal to the CAS, Ms Jeptoo requests that the challenged decision be set aside and that the two-year suspension be lifted," the CAS said in a statement.
Meanwhile, it added: "The International Association of Athletics Federations (IAAF) also filed an appeal, requesting that the athlete's period of ineligibility be increased to four years, due to aggravating circumstances which it argues warrant an extended period of ineligibility.
"With her appeal, Ms Jeptoo filed an application to stay the execution of the challenged decision. Ms Jeptoo requests this stay in order to be able to resume training and to be able to participate in IAAF competitions during the CAS proceedings."
Both appeals were currently "in progress and are being conducted in accordance with the Code of Sports-related Arbitration," the CAS said.
Jeptoo, winner of the last two consecutive Boston and Chicago marathons, is the biggest name in Kenyan athletics to have been caught cheating and the scandal has cast a shadow over the achievements of the east African distance running powerhouse.
She has already been denied the $500,000 (Sh45 million) prize for winning the last World Marathon Majors series.