Helensburgh’s fire station also contains the potential dangerous material, with a Scottish Fire and Rescue Service boss saying they don’t have the budget to rebuild stations that are at risk.

They questioned drivers from 04:00 to 06:00 on Sunday, one week on from the incident in Helensburgh. Thomas Sharkey, 21, and his eight-year-old sister Bridget died on the day of the fire.

The fire at the Sharkey family home in Helensburgh's Scott Court broke out at about 05:00 on Sunday. Thomas Sharkey Jnr died in the blaze, while his sister Bridget died later in hospital.

The fire at the Sharkey family home in Helensburgh's Scott Court broke out at about 05:00 on Sunday. Thomas Sharkey Jnr died in the blaze, while his sister Bridget died later in hospital.