British police believe 80 people died or are missing presumed dead after the Grenfell Tower blaze two weeks ago, but it will be many months before the full death toll is known, the officer leading the investigation said on Wednesday.

Fiona McCormack also said police believed no one survived in 23 of the London social housing block's 129 apartments. Police have identified and spoken to at least one person from each of the other flats.

She said 60 companies were helping police with their investigation.