The report did not in fact mention Mr Ryder. It also exonerated David Mitchell, the former Conservative whip under investigation, from using his position to dissuade the now-defunct Members Interests Committee from investigating allegations two years ago that Neil Hamilton MP had accepted cash for questions in Parliament.
The report criticised Mr Mitchell's appointment to a quasi-judicial committee as "a mistake" because he was a whip at the time.
Last night, Mr Ryder threatened to issue libel writs, saying he had instructed his solicitors to "threaten, and if necessary institute legal proceedings" against the BBC and The Guardian over the earlier reports unless they apologised and paid damages.
In a letter to the chairman of the Standards and Privileges Committee, the Leader of the Commons Tony Newton, Mr Ryder also warned that he reserved the right to start legal proceedings against the Privileges Committee member "suspected of being the source of the malicious briefing". He called on Mr Newton to carry out "an immediate and full investigation into this shambles", with witnesses interviewed in public on oath.
While the Standards and Privileges Committee report recommends that no appointments of whips to quasi-judicial committees should be made in future, it accepts Mr Mitchell's version that he was an unwitting party to events and had not realised that his appointment to the Members' Interests Committee would cause a row.
However, some Labour MPs are critical of the fact that the Privileges Committee did not summon any witnesses, other than Mr Mitchell.
One Labour source said: "This is another nail in the coffin for self- regulation." Yesterday's report contrasts sharply with an earlier report containing damning criticism of Tory minister David Willetts, accusing him of "dissembling". This report, published in December, led to his resignation.
The Standards and Privileges Committee will now consider the main complaint about Neil Hamilton accepting cash for questions, but it looks increasingly that it will fail to produce its report before the general election.
Committee on Standards and Privileges, Complaint of alleged improper pressure brought to bear on the select committee on members' interest in 1994 (further report), Stationery Office, pounds 8 80