Police and prosecutors are accused of keeping under wraps the identity of police spy Jim Boyling in another case

Another intriguing slice of Jim Boyling's undercover work has come to light.

Police and prosecutors face fresh allegations that his true identity was kept secret in another criminal trial of activists.

We have published this story on the latest allegations, and BBC Newsnight also broadcast an item last night.

Boyling went undercover in the 1990s under the alter ego of Jim Sutton to infiltrate environmental and animal rights groups.

Back in October, it was alleged that police chiefs had authorised undercover officers to give false evidence in court in order to protect their fake identities.

The allegations centred around a court case in 1997 when Boyling, then embedded in the Reclaim the Streets environmental group, was prosecuted alongside a group of protesters for occupying a government office in a demonstration. It was alleged that Boyling gave a false name and occupation throughout the prosecution.

Now the focus has switched to a second court case, a year earlier, when Boyling was pretending to be a campaigner against fox hunting.

This time around, Boyling is alleged to have said he was "delighted" to give evidence in support of four activists who were being prosecuted for public order offences. In a draft witness statement, he describes his occupation as "contract cleaner". Seems like that description was not quite the full picture.

The new allegations have made public by Mike Schwarz, the Bindmans lawyer who has been around for so long that he represented the activists back in 1996 and the activists arrested in the 2009 planned protest at the Ratcliffe-on-Soar power station.

The latter is of course the case in which prosecutors and police failed to disclose the involvement of another undercover policeman, Mark Kennedy, in a criminal trial.

The questions, it seems, continue to mount.