German prosecutors leading the investigation into a far-right demonstration in Chemnitz have said there is no evidence a video showing protesters chasing down and attacking a foreigner is fake.

The claims came in response to comments from Chancellor Angela Merkel’s domestic spy chief which questioned the authenticity of the recording.

Dresden prosecutor Wolfgang Klein told Die Zeit newspaper the video was part of the body of evidence his office was using in their investigation of the spontaneous August 26 protest which drew hundreds angered by the killing that day of a German man.

“We have no indications that the video could be a fake,” Mr Klein told the newspaper.

An Iraqi and a Syrian have been arrested on charges of manslaughter in the stabbing, which authorities say occurred after a verbal confrontation escalated.

Several migrants were hurt in the protests and Mrs Merkel’s spokesman said foreigners had been targeted and “hunted” by the far-right. Mrs Merkel herself condemned the “hate on the streets”.

However, on Friday, Hans-Georg Maassen, head of the country’s domestic spy agency, told Bild newspaper he was sceptical that far-right protesters in Chemnitz had “hunted” foreigners down and questioned the authenticity of the video, suggesting it may have been shot elsewhere or at a different time.

Zeit newspaper reported it examined the clip, and video shot shortly before, on the mobile phone on which it was filmed and confirmed it was from the August 26 protest.

Many have questioned Mr Maasen’s motives for his remarks and on Saturday lawmaker Patrick Sensburg, Mrs Merkel’s party’s intelligence expert, said he would be brought before the parliamentary intelligence committee to explain.

“Maasen will now have to explain how he came to his assessment and why he made it known in the media,” Mr Sensburg told the Handelsblatt newspaper. “If it is based upon classified evidence, he will have the opportunity to present it to lawmakers in the parliamentary panel next week.”

The day after the killing, some 6,000 took to the streets in Chemnitz in a protest that brought together neo-Nazis, members of the far-right Alternative for Germany party and other Germans concerned about crimes committed by migrants. There were scattered clashes with a smaller group of counter demonstrators.

Subsequent right-wing demonstrations have dwindled in size, most recently when 2,350 marched on Friday night in a rally that was primarily peaceful.

At the same time, about 1,000 marched in a counter demonstration and more than 5,000 attended a free open-air performance of Beethoven’s 9th Symphony held under the motto “against xenophobia, hate and violence”.