A swastika carved into wet cement has been swiftly removed by a council after a Jewish passer-by reported it.
But the man was shocked to be asked by a call centre operator: "What is a swastika?" and "is it offensive?"
The motif had been carved into cement sealing a drain cover outside a newly-renovated house in Frognal, Hampstead, and close to several Jewish homes.
The man, who was not prepared to be identified, rang Camden Council and says he was first asked to explain what a swastika was before being asked how he felt about it.
He said: "I was walking and glanced down and it caught my eye. Because it was in the concrete it must have been done when it was wet.
"The council removed it quickly, at least that's a positive. But I was surprised to be asked a question like that.To be honest, this is something I fear is constant throughout the UK and not specific to Camden Council. If people are not educated as to what a swastika is, how can they be expected to know if it is offensive?"
Camden said the practice of asking whether graffiti is offensive is a stock procedure where the 24-hour removal service is concerned and was never intended to cause offence.
A spokesman said: "If someone finds the graffiti offensive we'll remove it in 24 hours, if it's not offensive and is of a more general nature it'll take longer."
He blamed the response: "What is a swastika?" on a poor phone line and that the operator had initially misheard what the caller had said.