The Vatican has unveiled restoration plans for the canopy over the main altar of St Peter's Basilica in Rome.

The 400 year old canopy, which was designed by Renaissance master Gian Lorenzo Bernini, is over 30 feet tall and has stood over the tomb of St Peter since 1634.

The work will begin in February and is expected to last around ten months.

The canopy which is also known as a 'baldachin' was last restored in 1758. 

Announcing the restoration project at a news conference, the head of the office responsible for the upkeep of the basilica, the Fabbrica di San Pietro, said scaffolding would be built around the structure before Holy Week. Alberty Capitanucci said it was vital to intervene because damaging cracks have appeared since its last restoration. It's believed the damage has been partly caused by a microclimate inside the basilica which changes because of the continuous flow of visitors.  Over 20 per cent of the canopy is made of painted or gilded wood which is sensitive to humidity and variations in temperature.

The project is expected to cost 700,000 euros and will be entirely funded by the US-based Knights of Columbus.

The Vatican says all papal liturgical ceremonies will continue to take place at the altar during the restoration process.