A London hate preacher jailed after calling for 9/11-style attacks across Europe has sparked fresh outrage after defending the kidnapping of more than 200 Nigerian schoolgirls.

In videos posted online, Mizanur Rahman praises Boko Haram, the terrorist group behind the kidnapping, for angering the West and suggests it is “not necessarily a bad thing” if they kill non-Muslims.

Scotland Yard detectives are now probing the videos after being alerted to them by the Standard.

Haras Rafiq, head of outreach for the counter-extremism think tank the Quilliam Foundation, said: “These videos are dangerous because what he’s doing is creating an ‘us and them’ situation and leaving people angry with a clear enemy.

“The comments he’s made about Boko Haram are particularly dangerous, appalling and disgusting. He’s teaching how to hate and anger non-Muslims. That is a real threat to society and needs to be countered.”

Chair of the Home Affairs parliamentary committee Keith Vaz said: “I am deeply concerned by the content of this video.

“No child or young person should be exposed to these extreme views.

“The Committee recommended in its last report that more should be done to increase funding to counter message projects. It is vital that communities lead the fight against this type of extremism.”

In a video posted last week Rahman, a student of firebrand preacher Anjem Choudary and banned cleric Omar Bakri, says: “People want to make it out as though history began on the day these girls were taken from – sorry I should say these women – were taken from this high school in Nigeria.

“They didn’t do to these girls what the Nigerian government had been doing to the Muslims all these years – they didn’t rape anybody, they didn’t torture, they didn’t murder any of these girls.”

He then rants about the group being “full of good messages”, including its support for al-Qaeda. In another video, he says there is “not any evidence” the group has targeted Muslims or non-Muslims, adding: “I’m not saying it is or isn’t [a problem to kill non-Muslims].”

Violence linked to Boko Haram has resulted in an estimated 10,000 deaths between 2002 and 2013, including attacks on Western tourists and the bombing of churches, mosques, schools and police stations.

Last month’s kidnapping of the schoolgirls sparked fresh international condemnation.

When confronted by the Standard, the preacher, from Palmers Green, north London, said: “On the one hand people are portraying them [Boko Haram] as crazed lunatics who don’t know anything about Islam or society in general. But on the other hand if you actually read their messages they are not trying to destroy society, they are just complaining about the oppression against them and trying to better society.

“Of all of their messages, some are good messages so they are full of good messages. What I’m trying to do is tell people the whole story.”

Rahman was jailed for three years in 2007 for stirring up racial hatred after a protest at the Danish embassy over cartoons depicting the prophet Muhammad. During his trial, the Old Bailey heard he had said: “Oh Allah, we want to see another 9/11 in Iraq, another 9/11 in Denmark, another 9/11 in Spain, in France, all over Europe.”

A Scotland Yard spokesman said: “We are aware of the video and are assessing its content.”

•Adapted from a London Evening Standard report.Photo shows London hate preacher Mizanur Rahman.