Channel 4 has apologised for causing offence with a broadcast of The Simpsons.

A number of viewers complained about a song in the episode A Streetcar Named Marge, broadcast last month, which mocked the city of New Orleans.

They felt that the scene was insensitive, given the devastation caused by Hurricane Katrina.

The station broadcast an apology two days later – but another viewer complained to the Ofcom watchdogs, which delivered its verdict today.

In its ruling, the body said: ‘The speedy apology by Channel 4 was welcomed and appropriate. In view of this we consider the matter resolved.’

The broadcaster also told the regulators that it was tightening up its procedures to vet programmes in advance to avoid a similar situation happening again.

As the reference to New Orleans was incidental to the story about Marge joining a local amateur dramatic production of A Streetcar Named Desire, it was not flagged up as a potential risk in programming notes.

As well as the on-air apology, Channel 4 also contacted viewers who had complained to say sorry directly.