The beam that collapsed in the Scottish Parliament was due to a faulty bolt according to report.

Experts have blamed a faulty bolt for the collapse of a beam at the Scottish Parliament building.

A report by structural engineer Arup issued last night said that a connecting bolt was broken, causing the accident last week when a beam was left hanging above MSPs' heads. But Arup said it had yet to establish why the bolt was damaged.

Arup warned that engineers will have to check other bolted connections for signs of damage following the incident. A spokesperson said: "'Once the cause is established it will be necessary to confirm on site that all of the other bolts and connectors have been correctly installed and are not overstressed.''

The Scottish Parliament Corporate Body said it was disappointed at the report's brevity and announced its was making plans to hire a make-shift debating chamber for a second week.

The body has also appointed Atkins to aid Arup and the Health and Safety Executive in investigating the incident.