IAAF reintroduce four-year doping bans

The International Association of Athletics Federations (IAAF) have announced the reintroduction of four-year bans for athletes found guilty of doping.

In 1997, the length of bans was cut to two years, but recent high-profile cases involving Tyson Gay and Asafa Powell has forced the IAAF to make a change.

"The IAAF has an ethical obligation to the overwhelming majority of athletes and officials who believe in clean sport," read a statement.

"The new WADA (World Anti-Doping Agency) code, which will come into force on January 1, 2015, will reflect our firm commitment to have tougher penalties and the IAAF will return to four-year sanctions for serious doping offences.

"As a leader in this fight the IAAF has built and delivers a programme that is well resourced, far reaching, sophisticated and increasingly able to detect and remove from the sport those who breach our anti-doping rules."

The new measures will take effect from 2015.