By Geoff Adams-Spink
Age & disability correspondent, BBC News website
Thalidomide was originally sold as "totally harmless"
The Spanish authorities have told the BBC that the birth-defect drug, thalidomide, was sold between 1957 and 1961.
The admission will be seen as a victory for thalidomide campaigners who want their condition to be recognised.
Until now the health ministry has refused to confirm that the drug was sold, which has led to confusion.
A one line email was sent to the BBC which simply says: "Thalidomide was sold in Spain between 1957 and 1961."
The president of AVITE - the Spanish thalidomide association - Pepe Riquelme said "It's very, very important for us that they have finally admitted this.
"It's a big step. It confirms what we knew - that we have been fighting for the right thing for all these years.
"It opens up a new path for us. It's going to be a long struggle, but we will win in the end."
Thalidomide - sold as a remedy for morning sickness and as a sedative - caused thousands of babies to be born with disabilities around the world.
It was originally developed and manufactured by a German company, Chemie Grunenthal, and was withdrawn from sale after the link between its use and birth defects was established in 1961.
In most countries where it was sold compensation was paid to thalidomide survivors either by pharmaceutical companies, governments or a combination of both.
But in Spain - which was under a fascist dictatorship at the time - no admission about the use of the drug was made and those affected were given little or no information.
Those who believe that their disabilities were caused by the drug formed AVITE in 2003 and have been campaigning for compensation and recognition from the Spanish government and from Chemie Grunenthal.
Pepe Riquelme founded AVITE to get recognition for thalidomiders in Spain
Because of the lack of clarity over whether and how much thalidomide was sold in Spain it is difficult to determine how many people were affected.
AVITE has around 150 members with disabilities typical of the damage caused by the drug.
Mr Riquelme says that he is disillusioned with politicians who, in the past, have promised to help the thalidomiders but who have yet to make good their promises.
The Spanish government has set up a process to find out how many people were disabled as a result of thalidomide but - according to AVITE - even those who can prove that their mothers took the medication have only been told they are "probably" thalidomiders.
And the association says that the body responsible for determining thalidomide damage has refused offers of help from doctors in the UK who are acknowledged experts in the field.
The clarification from the government - although a welcome first step for the campaigners - still leaves matters somewhat confused.
According to Chemie Grunenthal, thalidomide was only sold in Spain between 1960 and 1961.
Although he welcomed the announcement, Mr Riquelme said: "We feel sad because we have been told that the process of establishing who has been affected by thalidomide was completed in March, but we have not heard anything from the government. We have no idea what they are going to do. It is already November and many victims still have not received the results of their tests. There is a huge amount of uncertainty in the air."
Crossing Continents on BBC Radio 4 reports on thalidomide in Spain on Thursday November 8 at 11.00 GMT.