Monte Carlo - The tighter whereabouts system, under which athletes must be available for drug tests 60 minutes each day, is fair and vital in the fight against doping, the ruling athletics body IAAF said on Thursday.

The IAAF said in a statement that its athletes have had a similar system for a dozen years and that the issue only became prominent now that other sports have to follow it under the new World Anti-Doping Code regulations.

The new system for out-of-competition testing has been criticised by athletes across the world of sport in recent weeks.

"While acknowledging the burden placed upon athletes, the IAAF believes that the whereabouts system is both proportionately fair as well as absolutely mandatory for the effective fight against doping in sport," the IAAF said.

The IAAF said "extensive measures" are implemented to end concerns from clean athletes about unintentional whereabouts failures. Three missed tests constitute a doping offence.

"It is not the intention of the IAAF or these new rules to punish athletes for administrative errors, but to test them effectively," the statement said.

The IAAF also quoted Croatian high jump world champion Blanka Vlasic, Japanese hammer thrower Koji Murofushi, and British marathon world record holder Paula Radcliffe as supporting the new system.

"It is fine, a system I am used to. Obviously sometimes it can be a hassle and something I always have to remember but a small price to pay to work towards clean sport ... For truly international fair testing everywhere we need this," Radcliffe said. dpa jb gb