A former undercover police officer has denied sleeping with women he was spying on because he thought “the ends justified the means”.

Ex-Metropolitan Police officer Bob Lambert, who infiltrated north London campaign groups in the 1980s, claimed he entered his deployment with no intention of engaging in any sexual relationships.

But he was confronted at the so-called “spy cops” inquiry with past comments suggesting superiors warned him that it was “going to happen” so he should just “keep it casual”.

He also said in a past interview that bosses were “concerned” before his deployment that he was “not like other police officers who were kind of well-versed in sexual relationships”.

“The management were aware that I wasn’t sort of experienced in the way that some colleagues were at the time and maybe, you know, and maybe that was a little bit to my detriment,” he said in 2013.

Lambert took the stand at the Undercover Policing Inquiry on Monday, December 2, after weeks of testimony from people he spied on.

Witnesses have included women who said he engaged in sexual relationships with them, one of whom said he fathered her baby.

Former animal rights activists testified that Lambert, instead of just spying on them, planned and carried out violent attacks.

He is accused of vandalising a Golders Green McDonalds, carrying out an arson attack on an animal testing boss’s home and planning bombings of Debenhams stores in Romford, Harrow and Luton.

Witnesses have claimed Lambert personally planted an incendiary device in the Harrow store, causing hundreds of thousands of pounds worth of damage.

He has previously admitted having relationships with women he spied on, but denied involvement in any crimes.

Asked on Monday what the managerial attitude was to undercover officers participating in crime, he said: “That it could only be countenanced where it arises in circumstances that the officer had no control over.”

He said it would be “a case by case judgement”, but there would be a threshold officers could not cross.

“Which side of that threshold would arson sit?” asked David Barr KC, lead counsel to the inquiry.

“That would sit outside of it,” said Lambert.

Bob Lambert on a demonstration whilst undercover as an animal rights activistBob Lambert on a demonstration whilst undercover as an animal rights activist (Image: Published by the Undercover Policing Inquiry) Members of the public were told off by chairman Sir John Mitting for erupting into laughter when Lambert denied he had ever taken drugs whilst undercover.

Lambert joined the Special Demonstration Squad (SDS) – part of Special Branch – in 1983 and spent nine months in a back office role before being deployed, undercover, for four-and-a-half years.

He testified that he had been tasked with infiltrating London Greenpeace and the Animal Liberation Front with a view to eventually also spying on the Animal Rights Militia.

But, he testified, SDS had also spied on racial justice campaigns like the Hackney Police Monitoring Group.

He told the inquiry he had assumed the identity of a dead child and set about “legend building” – meaning, creating a back story.

“It’s right, isn’t it, that there was nothing built into your undercover legend to deter sexual relationships or sexual activity?”

“No,” said Lambert.

“Why didn’t you do that?”

“I can’t recall.”

“You had been told there was a risk, hadn’t you?”

“Um, yes.”

“You were married?”

“Yes.”

“Why didn’t you build something into your legend to enable you to deter sexual activity, to give you an excuse not to do it?”

“I can’t recall now why.”

“Was it because you were contemplating getting involved in sexual activity?”

“No, I can be certain that that wasn’t the case.”

Bob Lambert told the Undercover Policing Inquiry he had never been instructed not to sleep with women he was spying onBob Lambert told the Undercover Policing Inquiry he had never been instructed not to sleep with women he was spying on (Image: Undercover Policing Inquiry YouTube Page) "Were you ever told not to get involved in sexual activity with members of the public?" asked Mr Barr. 

"I was never told that as a direction," said Lambert. "Never."

He was asked why, if this was the case, he had described his training in a 2013 interview as “first rate”.

“Was that because you overlooked the question of sexual relationships in making your assessment of the training?” asked Mr Barr.

“Erm, I don’t think so,” Lambert replied.

“Was it because you thought that the sexual relationships were not a very serious matter?”

“No, I don’t think, in 2013, that certainly wasn’t my understanding.”

“Did you think, then, that the ends justified the means?”

“No,” he said.

“So why did you say that your training was first rate, despite what you had been told about sexual relationships, without being told that they were problematic?”

“Well, I can’t add anymore to it at this stage,” he said. “I don’t recall.”

Lambert, who also infiltrated Islington Animal Rights, is due to continue giving evidence for the rest of the week.