Harriman, a long-time friend of Harry and Meghan, Duchess of Sussex, who took the couple's engagement photographs, was wearing an Anti-Apartheid Club T-shirt.
The Southbank Centre boss, who last month announced he was stepping down from the role, has been embroiled in allegations of insensitivity towards the Jewish community.
Among them is a claim he compared the rise of Reform UK to the conditions present in the run-up tothe Holocaust.
Critics have also argued that Harriman's frequent interventions on political issues, particularly the Israel-Gaza conflict and UK politics, risked undermining the political neutrality expected of charity trustees. Charity Commission guidance states that trustees must act solely in their charity's interests and avoid exposing it to undue political controversy.
Following the stabbing attack in Golders Green in April, Harriman was further criticised for sharing material suggesting there had been a media "conspiracy" to focus on the two Jewish victims, while giving less attention to an earlier stabbing of a Muslim man by the same alleged attacker.
Critics said the posts risked misrepresenting the nature of the attack. Harriman has rejected that characterisation.
He has also faced criticism for reposting a claim alleging that Ivanka Trump and her husband Jared Kushner were "selling off the Albanian coastline to Jewish billionaires and an Israeli military project" – a post he later deleted.
Culture Secretary Lisa Nandy contacted the The Charity Commission and the Arts Council and asked them to look into Harriman after more than 64 MPs and peers called for an investigation into his prolific use of social media.
Misan Harriman (Getty Images)Getty Images for SXSW London
Speaking to the JC, a spokesperson for the Board of Deputies said: "This was a misstep by Prince Harry, from whom we would have hoped for more caution given past unfortunate incidents."
Also reacting to the picture, the Campaign Against Antisemitism (CAA) said: “Prince Harry and other public figures should promote inclusivity and shun those whose conduct risks making cultural spaces uncomfortable for Jewish attendees.”
Harry's visit also includes engagements connected to his charitable patronages, and coincided with a High Court ruling dismissing his unlawful information-gathering claim against the publisher of the Daily Mail.
The Duke is travelling without Meghan or their children, Prince Archie and Princess Lilibet, after police protection was reportedly denied. He is expected to remain in Britain for only a few days.
