More than 1,100 victims of the 9/11 terror attacks on New York’s World Trade Centre are destined to remain unidentified.

The remains of as many as 1,000 people lost in the World Trade Centre attack might never be identified, according to the forensic biologist leading the DNA identification project.

The massive clean-up operation at the site of the collapsed World Trade Centre towers in New York could take up to a year to complete, it was announced today.

Crews working in the smouldering ruins of the World Trade Centre have begun assembling giant cranes capable of lifting hundreds of tons of debris at a time.