The Foreign and Commonwealth Office remained tight-lipped this week after the arrest of a senior official for an alleged antisemitic outburst.

Rowan Laxton, head of its South Asia desk, reportedly shouted “F*** Jews, f*** Israelis”, after watching pictures of Israeli action in Gaza on TV last month. He allegedly made his outburst while exercising in the gym of the London Business School.

The diplomat denied making anti-Jewish remarks, according to the Daily Mail, which had reported the allegations.

An FCO spokesperson, confirming that a member of its staff had been suspended, said: “No judgment has been made by the FCO regarding the allegations. This is a matter for the police.”

Mr Laxton briefs Foreign Secretary David Miliband on India and Pakistan.

Details of the incident emerged just before next week’s two-day international conference on tackling antisemitism, hosted by the Foreign Office.

Jon Benjamin, chief executive of the Board of Deputies, said: “This is a particularly shocking allegation in view of the official’s position.”

But he added: “The alleged activities of one individual, however embarrassing, should not detract from the good work that the FCO and many committed staff are doing in relation to a conference of great significance in the battle against antisemitism.”

Sarah Seedsman, director of alumni relations at the London Business School, said, in a statement circulated internally: “We are aware of this alleged incident, are co-operating fully with police inquiries, and keeping the matter under review. For the record, London Business School abhors and will not tolerate any racist or sectarian behaviour on campus.”

In the wake of the arrest, she urged participants in the school’s electronic discussion forum to “avoid inflaming the issue further”.

One report to the JC claimed that “someone said something untoward on the LBS discussion board about the diplomat incident.

“The School stepped in, said the remark was unacceptable, the student publicly recanted and now the discussion has been locked down by the School.”

A Metropolitan Police spokesman said that on January 27, a 47-year-old man had been arrested for “using threatening words and behaviour” intended to stir up religious hatred.

He has been bailed to return to a central London police station at the end of March.