The Press Association, via The Guardian reports:

Police 'secretly taped Damian Green arrest' Press Association

guardian.co.uk, Wednesday 24 December 2008 02.47 GMT [...] The Met said: "A tape sound recording was made of the MP's arrest and subsequent period in police charge, without his knowledge, prior to arrival at Belgravia police station from Kent. "This was authorised at superintendent level to provide an accurate record of anything that may have been said by officers or the MP over a period of nearly two and a half hours. "This was done with the best of intentions but to ensure total transparency this matter has been voluntarily referred to the Office of the Surveillance Commissioners for their advice." "The Crown Prosecution Service are also aware of this information which would be fully disclosable if any proceedings were to take place."

It is not good enough to spin and claim that "This was done with the best of intentions", it is still in contravention of the existing Statutory Codes of Practice, and is probably enough on its own, to get the whole case against Damian Green MP, such as it is, thrown out in a court of law.

The Office of Surveillance Commissioners, is meant to be consulted before the use of covert electronic bugging devices. Only in fast moving tactical situations, e.g. an ongoing kidnap / ransom etc. is it permissible to "fill in the paperwork" immediately afterwards.

That obviously does not apply to the arrest of Damian Green MP.

This secret audio bugging is obviously a contravention of the existing Police and Criminal Evidence Act statutory codes of practice, where recording of interviews by the Police, requires, firstly that they are not secret, and that two copies of the tape or other recoding media are produced, which are sealed and then signed, with one copy being given into the custody of a Police officer who is not involved directly in the investigation.

PACE Code E: Code of Practice on audio recording interviews with suspects (.pdf)

2.1 Recording of interviews shall be carried out openly to instil confidence in its reliability as an impartial and accurate record of the interview.

That is to provide a legally robust audit trail, and to prevent sneaky editing or forgery of the taped interview by the Police or others - such abuses have happened in the past.

None of those PACE safeguards apply to secret recordings as described in the Metropolitan Police statement above.

As usual, some Obvious Questions, which the mainstream media journalists etc. should be asking: