A Spanish court has ordered that the 200 bags of blood seized in the Operation Puerto police raids in 2006 must be released to the sporting authorities for drug testing.

This follows a successful appeal by the International Cycling Union, Italian Olympic Committee, Spanish Cycling Federation and World Anti-Doping Agency against a 2013 decision to destroy the blood bags.

That decision followed the conclusion of lengthy criminal proceedings against the doctor at the centre of the doping scandal, Eufemiano Fuentes, and four co-defendants.

Judge Julia Patricia Santamaria gave Fuentes a suspended one-year sentence for endangering public health and handed Jose Ignacio Labarta, an official from the Kelme cycling team, a four-month suspended sentence.

But those sentences have now been overturned by the appeal court as it has decided no offence was committed under the laws at the time of the raids a decade ago.

The other three defendants in the original trial, including Fuentes’s wife, a former Spanish Olympic hurdler who tested positive for drugs shortly after the 1988 Olympics, were acquitted.

The decision by the appeal court in Madrid to acquit Fuentes and Labarta will surprise many but not as much as the decision to release the blood bags, which belong to 35 different athletes and have been stored in a freezer at Barcelona’s anti-doping laboratory for a decade.

Most anti-doping experts had given up on ever getting the chance to discover who they belong to, although it remains unclear if any sporting sanctions will result from the tests as the statute of limitations for doping cases in 2006 was eight years.

The appeal judges said they were overturning the 2013 decision to destroy the blood bags in order to help the “fight against doping in sport”.

They added that destroying the blood bags might “create the danger that other athletes may be tempted to take drugs, sending a negative message that the end justifies any means”.