London Olympics officials have said reports that the futuristic roof of the velodrome planned for the 2012 games is to be built of steel rather than timber are “premature”.

Proposals in the winning design for a largely timber velodrome are believed to be under threat due to cost pressures, with steel now thought to be in the frame for the roof structure.

A spokesperson for the Olympic Delivery Authority would not confirm a review of materials was under way, but said: “Final decisions about the use of materials for the velodrome have not yet been made, but we have not discounted the use of timber and we are working closely with the architects to ensure timber remains an integral part of the design.

“The detailed velodrome designs are now being further developed following thorough consultation with the architectural community where the plans have been praised by senior figures.”

Supporters of timber had hoped that the velodrome and aquatics centre would be showpieces for sustainable materials. Although the aquatics centre has retained timber cladding on the roof, the frame is to be made of steel rather than glulam.

A decision to favour steel for the velodrome would be a further blow to timber industry Olympic lobby group Wood for Gold.