The inquest into the death of Bob Woolmer has been put on hold amid suggestions that the Pakistan cricket coach may have been poisoned with a deadly plant toxin.

The Jamaican justice ministry said last night that there had been "recent and significant developments" in the case, and as a result the coroner had decided that the inquest should be delayed until further notice.

Woolmer was found dying in his hotel room on March 18, during the cricket World Cup tournament in the West Indies. Post mortem reports on the cause of death were inconclusive at first, and it was only four days later that the coroner tentatively suggested that Woolmer had been strangled.

The killing caused a tremendous scandal. Allegations that the former Kent and England player had been silenced to stop him blowing the whistle on match-fixing in Pakistan cricket competed with counter-allegations that he had been murdered in hot blood by a fan furious that the Pakistan team, who had been among the favourites to win the tournament, had just been unexpectedly ejected after losing to cricketing minnows Ireland.

For the first month a team of 30 detectives took more than 100 witness statements and pored over CCTV footage from the 12th floor corridor at the Pegasus Hotel in Kingston, but seemed to make little progress.

Detectives at Kingston police station were allegedly tipped off at the end of March by a caller with a Pakistani accent, claiming that Woolmer had not been strangled but dosed with aconite, a nerve poison linked to several political assassinations in Pakistan.

The inquiry appears to have gained new focus since the toxicology reports came back last Thursday.

Mark Shields, the Jamaican Deputy Police Commissioner and a former Scotland Yard detective, who has been leading the investigation, refused to make the results public at the time, saying they were going to need further analysis and investigation.

A senior police source quoted in The Sun today said: "The toxicology tests show that he had significant traces of aconite.

"We are now entirely convinced that he was poisoned. The fact that aconite has also previously been used in Pakistan may also be highly relevant."

The roots of several species of the aconite, or wolfsbane, plant contain high concentrations of the alkaloid pseudaconitine, a deadly nerve poison known as bikh or nabee in Pakistan and northern India.

Very small quantities are fatal. In 2004 Andre Noble, 25, an actor, died after accidentally eating part of an aconite plant on an island near his native Newfoundland.

Eating aconitine causes violent vomiting and diarrhea, before the victim's organs seize up and breathing slows. Death usually occurs within half an hour, through asphyxiation. The mind remains alert throughout.

Police are believed to be investigating how the poisoning theory could explain the crime scene. Woolmer was found in his bathroom amid a scene of chaos, with quantities of vomit on the floor and mirror.

There were injuries on his nose and neck, but it has been reported that there were no signs of manual strangulation or wounds from a fight - a puzzling fact as Woolmer was 6'1" and strongly built, and would have been expected to put up a struggle if attacked by intruders.

Detectives are reported to be investigating whether the wounds could have been caused by Woolmer's striking his head on the bath or toilet when he fell.

The inquest to determine how he died had been scheduled to start on Monday, with several of the Pakistan team expected to be called back to Jamaica to give evidence.

"The coroner wishes that these new and significant developments be pursued with the utmost urgency, taking into account that the officer in charge has advised that these new developments are critical to the progress and the eventual results of the investigations themselves," said the Jamaican justice ministry, in a statement.

"If it becomes necessary for an inquest to be held after the new and material developments have been investigated, then another date for the holding of the inquest will be appointed."

Jamaican police initially questioned three Pakistan team members, including Inzamam ul-Haq, the then captain, before allowing the team to fly home. The West Indies and Ireland teams, which were staying in the same hotel, were also questioned and fingerprint and DNA samples were taken for the purposes of elimination.

Woolmer's wife, Gill, has said that she knew of no threats to her husband's life from a betting mafia in Asian cricket. She has been kept abreast of latest developments.