Concerns that Seroxat and others in the SSRI (selective serotonin re-uptake inhibitor) class, such as Prozac, could tip a minority towards suicide have been raised for a while.

In the US, two years ago, a jury awarded a family £4.6m damages after concluding that the drug, known there as Paxil, caused Donald Schell to kill his wife, daughter, baby granddaughter and then himself.

The medicines and healthcare products regulatory agency, part of the Department of Health, collects reports from doctors on any side-effects or adverse reactions that might be linked to a prescription medicine. Neither patients nor their relatives can fill out a "yellow card" - recording problems - and not every doctor participates in the scheme as it is voluntary.

The BBC's Panorama programme Emails from the Edge will reveal on Sunday that the phenomenal response - 67,000 phone calls and 1,400 emails - to its October documentary on Seroxat threw up reports of 16 suicides, 11 of them in the past two years, that have never been reported to the MHRA, as far as relatives are aware. The agency knows of only seven suicides of people on Seroxat over the past two years.

"In retrospect, when it is fully conceded that the drug can cause problems, this is going to look like a very serious failure," said David Healy, director of the North Wales department of psychological medicine, who has taken evidence to the agency linking suicides to this class of drug.

He added: "Doctors have been getting the mantra from the drug companies for 12 years that it is the disease [causing the suicide] and not the drug. It does provide a nice way out for GPs who just don't want to contemplate the possibility that a drug they prescribe could cause death."

One of those who contacted Panorama was Graham Aldred from Cheshire, whose wife killed herself after 11 days on Seroxat. Rhona, 53, suffered nightmares and then began to behave out of character.