Three-times Tour winner Contador, 27, said meat bought in Spain and consumed on the 2010 Tour's second rest day was responsible for the traces of the banned substance clenbuterol found in his urine sample.
He has been provisionally suspended by the International Cycling Union, faces a possible two-year ban and could lose his 2010 Tour title.
The Spanish meat producers' group said in a statement on their website they wanted a "rigorous investigation that established the facts once and for all."
An official probe would also oblige Contador to make his accusations about the meat in a formal legal setting rather than through the media, the statement added.
The Spanish Cycling Federation is expected to make a decision on the Contador case within three months.