Police investigating Bob Woolmer's death have received a tip-off that the coach was poisoned by 'aconite' believed to be the "perfect" drug to mask a murder.

According to Sunday Mirror, an anonymous man, thought to be from Pakistan, phoned police claiming that aconite killed the coach following which Jamaica's Deputy Commissioner Mark Shields, who is leading the probe, has ordered new tests on Woolmer's body to look for traces of the drug.

• Woolmer murder story

Aconite causes the victim's internal organs to seize and slows down their breathing until they finally stop. Death is usually by asphyxiation within 30 minutes and this explains how Woolmer died without putting up a fight.

"The aconite tip is a major breakthrough and is being taken extremely seriously. The man who called Kingston police station had a Pakistani accent and was very specific about aconite and how it was administered," Shields was quoted as saying by the paper.

"The symptoms Bob suffered before he died are identical to aconite poisoning, which is why it is a major line of inquiry now. It would also explain how such a physically imposing man, at 6ft 1in tall, died without putting up a fight. You'd struggle to get two people into his bath room let alone three, so it could be no-one was there," he added.

Toxicologists say aconite is the "perfect" drug to mask a murder. It also explains why Jamaican pathologist Dr Ere Seshaiah found no marks around his neck to suggest he had been strangled.

Toxicologist Prof John Henry, of St Mary's Hospital, Paddington, London, told the Sunday Mirror that "Woolmer would have felt nauseous after the drug began to work and would have gone to the bathroom to be sick. He wouldn't have realised straight away how serious his condition was, so it was doubtful he'd have phoned the hotel's reception."

"By the time he realised how ill he was it would be too late... The drug causes a loss of power in the limbs. Aconite works like cyanide... It makes the skin clammy and hands and feet tingly. It also causes vomiting and diarrhoea... All the while the victim's mind remains clear, so it is a cruel death.

"It is the perfect drug to make a murder appear to be a suicide because it leaves no mark on the body. It is difficult to detect in a post-mortem unless it was specifically looked for," he said.

Meanwhile, the Mail on Sunday said Woolmer, who was working on two books, feared harm by bookmakers since the 2000 match-fixing scandal broke.

When a reporter asked him to move to a quieter place like his room for a chat, Woolmer said "I feel more comfortable in public places."

Asked if he was worried about his safety, his replied "you don't know how those people (bookmakers) will react" and added someone might be upset at the news (about match-fixing) and take it out on him.

The paper also said Woolmer in his last interview had claimed to have rejected a 125,000 pounds bribe to fix an international match in Mumbai in 1996 when he was coach of South Africa.

"I've never betted on anything in my life. It was voted out handsomely. The players shoved it aside... what we did not know was that he (then South African captain Hanse Cronje) took money," Woolmer was quoted as saying by the paper.