Image caption The bronze statue of a child born with thalidomide symptoms is on display in Stolberg, Germany

The company which invented thalidomide has "insulted" those affected by the drug by issuing an "insincere" apology, campaigners have said.

The drug, sold in the 1950s as a cure for morning sickness, was linked to birth defects and withdrawn in 1961.

German-based Gruenenthal has issued its first apology in 50 years, but said the drug's possible side-effects "could not be detected" before it was marketed.

But the UK's Thalidomide Trust said any apology should also admit wrongdoing.

Nick Dobrik, a member of the trust's national advisory council, said it "should be an unreserved apology, not a conditional apology".

Within months of thalidomide first going on sale in Germany, doctors were writing to Gruenenthal asking about side effects that were appearing in their patients. The company's stock response was to say it was not aware of side-effects and that these must be down to the individual patient. The company muffled the alarm bells - its apology now is next to worthless. It changes nothing about the company being negligent in putting the drug on the market. Gruenenthal also tried, and almost succeeded, in dragging the legal process past the German statute of limitations to escape responsibility. Almost everything that Gruenenthal has done relating to thalidomide has been absolutely disgraceful.

"We feel that a sincere and genuine apology is one which actually admits wrongdoing. The company has not done that and has really insulted the thalidomiders."

Compensation

Martin Johnson, the trust's director, told the BBC that the news that the manufacturers were starting to acknowledge responsibility was welcome but they were still trying to perpetuate the myth that no-one could have known of the harm the drug could cause when there was, he said, much evidence that they did know.

And Freddie Astbury, president of Thalidomide UK, said: "It's taken a long time for them to apologise. There are a lot of people damaged by thalidomide struggling with health problems in the UK and around the world.

"So we welcome the apology, but how far do they want to go? It's no good apologising if they won't open discussions on compensation. They've got to seriously consider financial compensation for these people."

By the time the drug was pulled from the market, more than 10,000 babies worldwide had been born with a range of disabilities caused by the drug.

This included shortened arms and legs, blindness, deafness, heart problems and brain damage.

There are between 5,000 and 6,000 sufferers still alive. Thalidomide UK says there are 458 people in the UK who were affected by the drug, but that for every thalidomide baby that lived there were 10 that died.

Media playback is unsupported on your device Media caption Nick Dobrik: A sincere and genuine apology is one which actually admits wrongdoing

Harald Stock, Gruenenthal's chief executive, issued his company's apology at the unveiling of a bronze statue symbolising a child born without limbs because of thalidomide.

"We ask for forgiveness that for nearly 50 years we didn't find a way of reaching out to you from human being to human being," he said at a ceremony in the western German city of Stolberg, where the firm is based.

"We ask that you regard our long silence as a sign of the shock that your fate caused in us."

Thalidomide timeline 1953: Drug created in Germany by the Gruenenthal Group

1958: Thalidomide is first licensed for use in the UK

1961: Australian doctor William McBride reports an increase in deformed babies being born at his hospital to mothers who had taken thalidomide

Drug is withdrawn later that year

1968: UK manufacturers Distillers Biochemicals Limited (now Diageo) reaches compensation settlement following a legal battle by affected families

2005: Diageo doubles its compensation payouts from £2.8m to about £6.5m a year

2008: The drug is approved for the treatment of multiple myeloma - bone marrow cancer - by the European Medicines Agency

2009: UK government agrees a £20m grant, to be paid to the Thalidomide Trust over three years

2010: UK health minister Mike O'Brien makes a formal apology to thalidomide survivors on behalf of the government

Mr Stock said the company regretted that the potential for thalidomide to affect the development of foetuses "could not be detected by the tests that we and others carried out before it was marketed".

Class action

BBC science correspondent for the Today programme, Tom Feilden, said one of the main issues was what Gruenenthal knew about the drug's side effects, when it knew about them and whether the company could have acted sooner in withdrawing it from the market.

Some compensation has been paid, particularly by thalidomide's British distributor.

Gruenenthal itself has previously paid compensation to survivors of the drug, many in Germany, and has voiced regret over the issue - but has not admitted liability.

In the early 1970s, it agreed to pay 100m Deutschmarks (£40m) into an official fund for German thalidomide survivors and was given permanent legal indemnity by the German government.

Since the original fund money ran out, continuing compensation payments have been made by the government. In 2009 the company added a further 50m euro (£39.6m) one-off endowment.

Compensation claims are still outstanding, including one key class action in Australia, which saw thalidomide survivors win the right to have their case for compensation heard there.

The drug is still used today under strict controls to treat some bone marrow cancer patients.