Victims of the disastrous "Elephant Man" drug trial, in the UK in March 2006, have been warned that they face an increased risk of contracting cancer and other deadly diseases.
One of them, a 30-year-old man who has recently married, was told that he was showing "definite early signs" of lymphatic cancer.
Lawyers believe that Parexel, the US firm that ran the trial, could face a bill of up to £30 million in compensation.
Martyn Day, who represents four of the victims, said: "They face a lifetime of contracting cancers and all the various auto-immune diseases from lupus to MS, from rheumatoid arthritis to ME."
Last week Mr Day passed on a medical assessment by the immunologist Prof Richard Powell to his clients, who include Nav Modi, 24, from Forest Gate, east London, and three other men aged 19, 30 and 29.
Prof Powell wrote of patient A, the 30-year-old: "It is highly likely (more than 50 per cent) that A will develop auto-immune diseases and has definite early signs that a lymphoid malignancy is developing."
The man, who has not been named, is to meet doctors in the next few weeks to decide on a course of treatment. There is optimism about his chances of survival if it is dealt with at an early stage.
Six volunteers suffered multiple organ failure after they were paid £2,000 each to take part in the drug trial at Northwick Park Hospital in London in March.
Mr Modi said: "I have made the biggest mistake of my life. I feel like I've given away my life for £2,000. None of us is sure about the future. It could be that in six months' time we are dead."
Mr Day said the victims of the trial may be entitled to between £2 million and £5 million each in compensation.
This story comes as further evidence that the 'business with disease' is alive and well and worse, continuing. These unfortunate volunteers, who for £2,000 sterling, took part in the clinical trial of the drug known as TGN 1412 in March, have now learned that due to their increased risk of contracting cancers and auto-immune diseases they may be unlikely to live long enough to receive their £2 - £5 million compensation.