London: There was fresh scandal over the disastrous Northwick Park drugs trial yesterday as one human guinea pig told how he was refused his £2,000 (Dh13,300) fee in a voicemail message.

Raste Khan was told he would not be paid for his part in the trial unless he came back to hospital for more tests.

The 23-year-old was left a message on his mobile phone days after taking part in the trial, which left six people in intensive care one of whom remains critically ill.

Khan was given a harmless placebo drug, but watched as other volunteers who had been given the injection of TGN 1412, intended to combat, arthritis, leukaemia and multiple sclerosis, suffered horrifically.

Speaking as he prepared to launch a compensation bid, he said he was still waiting for an apology from Parexel, the American firm that tested TGN 1412 on behalf of its German developer TeGenero.

The student said: "I was left completely in the dark about what was going on and I have received no communication since the trial except an answerphone message warning that unless I went in for a follow-up test I would forfeit the agreed £2,000 payment."

He was not sure whether the message, one week after the trial, was from TeGenero or Parexel.

"It was not long after the trial and I was terrified of going back. I've not been able to sleep properly and am too frightened even to get sleeping pills. What I saw during that trial was very, very frightening. I still feel haunted by it."

The trial took place last month at a private clinic at Northwick Park Hospital in Harrow. Within minutes the volunteers who had taken the drug suffered horrendous reactions.

In the worst cases their heads swelled up to three times their normal size.

He said that despite repeated attempts he could not find out from the firm running the trial whether he was at risk, and was finally told by NHS doctors he had been given the placebo.

"I left repeated messages for Dr Daniel Bradford, in charge of the trial, but he did not reply," said Khan.

"For two days I had no idea what I had been given. My family and friends have gone through hell worrying about me."

He added: "I feel guilty that I was one of the two lucky ones given a placebo, but more than that, I am outraged at the way we have all been treated."

Parexel, the company that carried out the trials. was unavailable for comment.