Police have dropped an investigation into comments made by controversial former US marine Ken O'Keefe at an Israel Apartheid Week event.
Officers studied video footage of Mr O'Keefe telling an audience that Israel "must be destroyed", but decided no criminal offence had been committed.
Mr O'Keefe had responded to last week's news of the investigation by tweeting: "Bring it ****ing on."
During the debate at Middlesex University's Hendon campus last month, Mr O'Keefe compared Jews to Nazis and claimed Mossad was "directly involved" in the September 11 terror attacks on the United States.
There were heated scenes as Mr O'Keefe clashed with supporters of Israel following his comments. He was later reported to police by two audience members who believed he had incited racial hatred.
A Barnet Police spokesman confirmed: "The comments made were in an open debate and listeners were encouraged to agree or disagree with what was said.
"Officers have gone through the video clips and media material and have agreed that there are no criminal offences."
Baroness Tonge also spoke at the event, sitting next to Mr O'Keefe. She resigned the Liberal Democrat whip after refusing to apologise for stating at the Free Palestine Society event that Israel would "not last forever". Police also confirmed she would face no charges.
Jonathan Hoffman, co-vice chair of the Zionist Federation, said: "O'Keefe whipped up hatred against Jews who support Israel, which is the vast majority. It is the clearest case of incitement I have seen in many years of going to these hostile meetings. It is very sad that the law has yet again failed us."