A woman was being questioned by police today over a fire which devastated a 15-storey tower block.
The 32-year-old was arrested by officers investigating what sparked the blaze on the Cambridge Road estate in Kingston-upon-Thames, Surrey, yesterday.
Police said they were treating the fire as "suspicious" and specialist experts were expected to begin examining the scene today.
More than 100 firefighters raced to the flats as flames and plumes of black smoke poured from the building around 5pm.
The top four floors of Kingston Borough Council's Madingley block in St Peter's Road were damaged and dozens of residents evacuated but no-one was hurt.
A Metropolitan Police spokesman said the woman was being questioned at a south London police station.
A London Fire Brigade spokesman said: "The cause of the fire will be investigated as soon as it is safe to do so."