Spain's cycling federation justified its decision to seek a one-year ban for Alberto Contador, rather than the usual two years, by saying his responsibility appeared to be minimal, a Spanish newspaper said on Tuesday.

"The negligence of the cyclist was not significant ... as the simple presence of the substance in his body does not imply a violation of fair play," the federation, RFEC, said in a report, according to the sports daily Marca.

The paper said the federation used this argument to seek a one-year suspension, rather than a two-year ban that would normally be imposed for a doping violation.

The presence of the banned substance, clenbuterol, was detected over four consecutive days during last year's Tour de France, the RFEC said in its report, although only one of those tests, on July 21, was retained.

Contador himself said on Sept 30 that he was tested again on July 22 and that the amount of clenbuterol was "was much less than the previous day".

"That would correspond to a single ingestion (of clenbuterol) on July 21 and the normal time to eliminate the clenbuterol of three days," the head of the Madrid laboratory, Jesus Munoz-Guerra, said in the report.

The RFEC last month recommended Contador receive a one-year ban for his positive test for the banned muscle-building and fat-burning drug.

The rider denies any wrongdoing and says he unknowingly ingested trace elements of clenbuterol from beef brought from Spain to France during the second rest day of the Tour. He has vowed to appeal.