NAIROBI (AFP) -- Kenyan marathon runner Michael Njenga Kunyuga has been given an eight-year ban for doping offences, the Athletics Integrity Unit said on Friday, Nov. 4.

Kunyuga, 36, tested positive for the performance enhancing drug norandrosterone and was also found to have tampered with the anti-doping process, the agency said.

He becomes the second Kenyan long distance runner in just weeks to be punished for drugs offences, after marathoner Titus Ekiru was banned for 10 years in October.

Kenya has seen a surge in doping cases that have tarnished its reputation as an athletics powerhouse. Nearly 70 athletes -– mainly long-distance runners -– have been banned over the past five years.

The AIU said an investigation found Kunyuga had submitted false medical information to support his explanations about a positive drugs test after he placed second at the Riga marathon in Latvia in May last year.

Kunyuga's ban runs from the date of his provisional suspension on August 1, 2022.

"The athlete has failed to demonstrate that the anti-doping rule violations were not intentional," the AIU said in announcing the eight-year ban.

Kunyuga's race results since May 15 last year have been erased and he must forfeit all prizes and appearance money.

Kenya is one of seven nations -- including Belarus, Ethiopia and Ukraine -- listed as Category A under World Athletics' Anti-Doping Rules as deemed to have the highest doping risk.

In March, AIU head Brett Clothier warned during a visit to Kenya that the international anti-doping body was stepping up its investigations and testing in the country.

The AIU has said Kenyan athletes were being assisted in covering up doping offences by a "medically-savvy operation."