Crossrail has awarded a further four contracts through its enabling works framework.

• C201. Royal Oak Portal Taxi Facility Demolition - Keltbray
• C207. Demolition works for Crossrail Bond Street Station - McGee Group
• C208. Demolition works for Crossrail Tottenham Court Road Station - McGee Group
• C248. Pudding Mill Lane Portal - Costain Skanska JV

Martin Rowark, head of procurement for Crossrail said: "These early enabling works contracts are vital to the safe and efficient construction of the subsequent station buildings and other structures. The contracts are significant and complex in their own right and we are pleased to have awarded them on schedule."

Keltbray and the Costain Skanska JV were also winners in the first round of enabling works contracts awarded by Crossrail last month.

The government has warned that traces of bubonic plague or anthrax could be found at a site on the route of £16bn cross-London Crossrail scheme. Lord James of Blackheath warned that an area in the City of London to be used for tunnelling may be a missing 16th Century anthrax burial ground.

Transport Secretary Lord Adonis said that a compulsory purchase of the area, a car park, was expected to go ahead.

"We may very well have here at Number 10 Hayne Street the missing anthrax burial ground that has been lost for 488 years," Conservative Lord James said.

He said that churches in the area had "refused to accept the bodies of the 282 victims of the anthrax outbreak that wiped out the whole population of Hayne Street at that time".

The threat of diseases being released was raised by Lord James at the passing of the Crossrail Bill in 2009.

Human remains were found in May 2009 in a deep exploratory bore hole in Farringdon, central London, but they showed no traces of plague or anthrax.

Deadly anthrax spores can lie dormant for centuries but if disturbed can spread through the air.

The bacteria which causes bubonic plague can also survive in plague pits.

Lord Adonis said he accepted it was an issue that needed further study and Crossrail understands that there is a very small possibility of buried human remains being encountered during the works at 10 Hayne Street

"Crossrail understands that there is a very small possibility of buried human remains being encountered during the works at 10 Hayne Street," he told peers but said it was "highly unlikely that the works would release any anthrax spores or bacteria causing plague".

The Crossrail scheme is intended to link towns to the east and west of London with Heathrow, the West End, and Canary Wharf from 2017.