Spanish police have taken 84 people into custody and seized more than 700,000 doses of illegal doping products imported from Greece, China and Portugal, the Interior Ministry said today.

"Officers have dismantled two organizations importing the products, which can cause severe damage to health," the Ministry said in a statement.

In the first operation security forces arrested 75 people accused of using the postal service to introduce doping drugs from Portugal to then sell on in gyms and private homes in Madrid, Valencia, the Basque Country and Asturias. Police searched 47 homes seizing more than 24,000 doses.

Spanish police estimates that, during the first trimester of 2013, the organisation could have introduced doping substances valued at more than 11,000 euros per day.

The second ring used social networks to advertise and lure potential clients.

The organisation introduced the drugs from China and Greece in postal packs.

Police seized 683,000 doses of steroids, EPO and growth hormone and arrested nine people.

The operations were carried out in recent months.

The Spanish parliament approved a new anti-doping law this month designed to bring Spain into line with international norms and dispel the impression the nation is soft on doping.

Authorities hope the law will boost Madrid's chances of winning the right to host the 2020 Olympic Games.