The Spanish police released on Sunday 17 Portuguese, who had been detained two days earlier, suspected of selling false cocaine to English fans who went to Madrid to watch the final of the Champions League.
National Police source told the Lusa news agency that "the quality of cocaine is being analyzed" and there are doubts as to whether it is really that drug or an identical substance that was only to deceive the buyers.
Spanish law enforcement officials are also investigating whether suspects, aged between 21 and 39, who have been released, have some family relation between them, as it was initially reported that they were members of the same family.
After being heard by a security judge, who was said to have come from Lisbon to spend the weekend, the Portuguese were released, being investigated for alleged offenses "against public health."
On the other hand, a source from the High Court of Justice of Madrid told Lusa that the 17 Portuguese will be called to make more declarations "in the coming weeks or months".
"This is a serious crime, but it is not justified that they should be heard next," he added.
According to the newspaper El Mundo, the Portuguese were selling for 20 euros to Tottenham and Liverpool supporters, a gram of white powder that was actually a substance similar to cocaine, which they had bought at the pharmacy for 70 cents.
The Portuguese were arrested by undercover officers who were part of the security device set up to prevent changes to public order in the final of the Champions League, a game that took place on Saturday night.