Dozens of workers were switched from their duties in a major safety alert at Birmingham’s new £550 million rail station after a large quantity of white asbestos was uncovered.

The emergency procedure was ordered after traces of the material were found in the south-east corner of the old station. A total of 50 workers had to be evacuated from the affected areas.

The evacuation involved a variety of staff, including surveyors, demolition contractors and works contractors, who had to be moved to other areas of the complex as a precautionary measure.

Network Rail say there is no danger to members of the public using the station – but workers claim the full extent of the problem is still unknown while tests are carried out on the substance.

A worker, who asked not to be named, said: “The men were put on hold and the stuff has been taken away for examination. They were trying to hush it up but it is important that the public are made aware of what has happened.

“Loads of asbestos was found and some of the sub-contractors had to be stood down for days. It has created a lot of concern amongst the men.”

A Network Rail spokesman said the discovery of asbestos had been expected due to the age of the old New Street station.

The company said the asbestos scare would not delay the anticipated 2015 completion date but would increase the overall costs of the redevelopment scheme.

“Working on a building of this age we had expected and planned for encountering asbestos but perhaps not in the quantity and locations that have been recently uncovered.

“There is no danger to the public using the station and the areas have been sealed while we bring in specialists to remove it.

“Most workers have moved onto other areas and aspects of the redevelopment in the interim.

“We don’t anticipate this impacting on our 2015 finish date but extra costs are being incurred.”

The spokesman said the area sealed off following the discovery included mainly back-room offices, service and storage areas in the south-east corner of the old New Street Station.

The asbestos found is the less dangerous white strain, as opposed to blue. Network Rail said it was ‘perfectly safe if not disturbed.’

The spokesman added: “Surveyors, the demolition contractor and temporary works contractors such as scaffolders and temporary lighting installations have been re-allocated to other parts of the project where asbestos risk has been dealt with and clearance already given – around 50 guys in all.”

The spokesman said all the workers affected in last week’s incident had now been re-allocated to other duties.

“We were aware, via old paperwork, that an asbestos strip of the old concourse was done over a decade ago but it seems that the south-east corner with its back-room offices and larger service and storage areas were left.”

The station has remained open throughout the £550 million redevelopment to transform New Street. The new concourse opened in April, leaving Network Rail and its partner Mace to deliver the project.

Redevelopment work is underway on the old station concourse and the Pallasades shopping centre, which will be converted into a new shopping destination called Grand Central Birmingham.

The new complex will incorporate a four-storey John Lewis, more than 40 new shops and over 15 cafes and restaurants.

The redevelopment of New Street Station and the Pallasades Shopping Centre is backed by Birmingham City Council, Network Rail, the Department for Transport, Centro and Advantage West Midlands.

The station has remained largely unchanged since it was last redeveloped in 1967 and has been forced to cater for more than double the number of passengers it was initially designed to accommodate.