The shock move came after "new evidence" emerged over claims that Dallaglio took recreational drugs during a party celebrating the British Lions' Test series victory over South Africa two years ago.

He will still have to answer a charge that he brought the game into disrepute when he goes before the Rugby Football Union's disciplinary panel on Wednesday.

But it now seems certain that he will be available to play for England in the World Cup this autumn.

Team recall

The allegations against the former England captain arose from a story in the News of the World last May in which Dallaglio reportedly bragged about drug taking and dealing.

Dallaglio: "Bitterly regretted" experimenting with drugs

A detailed 10-week probe, conducted by a three-man panel under the chairmanship of High Court judge Sir John Kay, featured exhaustive enquiries and interviews, some with Dallaglio's playing peers, and resulted in the charges against him.

The Wasps and England flanker protested his innocence throughout and he has been supported by England coach Clive Woodward, who re-included him in the the national side's World Cup squad at the first opportunity.

Vehement denial

BBC Rugby Correspondent Ian Robertson: "This is not a major surprise"

Dallaglio will answer the disrepute charge before a three-man RFU disciplinary panel chaired by High Court judge Sir Oliver Popplewell, with RFU Council members John Spencer and Chris Tuffley filling the remaining positions.

The likely outcome now is that he will receive a retrospective ban - possibly three months - if the disrepute matter is proved, clearing him for England's World Cup opener against Italy on 2 October.

Dallaglio resigned the England captaincy on 24 May - the day after the story was published - and issued a vehement denial of the allegations.

He said that he had lied when he gave details of drug-related activities to two reporters who were posing as agents offering him a lucrative sponsorship deal.

He did, however, admit to experimenting with drugs when he was younger - something that he "bitterly regretted".

In the meantime, Dallaglio got on with his rugby, rejoining England's World Cup training squad and being recalled for the 108-6 victory over America two days ago.

David Laurenson: "It does not surprise me."

David Laurenson, the editor of Running Rugby Magazine, told BBC Radio 5 Live that he has always wondered how the RFU planned to investigate the claims.

The News of the World's case was undermined by its unwillingness to release an unedited version of the interview tape and its failure to name Dallaglio's two alleged British Lions accomplices.

The paper was also heavily criticised for its "honey-trap" tactics in acquiring the story.