Fire crews were called to smoke billowing from a 54ft motoryacht in the central London marina at 12.41pm today.

Firefighters wearing breathing apparatus boarded the vessel to put out the sparks.

The middle deck of the 10 tonne Edership President 54S was left severely smoke damaged inside.

A London Fire Bridgade spokesman said: ‘The fire was under control by 1.47pm.

‘Three fire engines from Whitechapel, Dowgate and Dockhead fire stations attended the incident.

‘Two fire rescue units from Edmonton and East Ham were also at the scene and the brigade’s fire boat was mobilised.’

William Bowman, marina director for St Katharine Docks, said the cause of the incident was ‘a fan heater, which burnt out, having been left on a timer.’

He said: ‘One of my staff spotted it during the lunchtime rounds. A lot of smoke was billowing from the stern.

‘All our emergency procedures kicked into action.

‘We’re proud of ourselves because we make all our boat owners fill out an emergency form, which list contact details, pictures of the boat and a list of all gas bottles, diesel and petrol on board.

‘When the fire service arrived we were able to let them know exactly what they were dealing with.’

He added: ‘The owner was away in the States when everything happened.

‘It’s a lesson to all boat owners that it’s not safe to leave fan heaters on, it really isn’t. This one was left on a thermostat.’