The Royal Institute of British Architects (RIBA) has warned its members to be vigilant following what appears to be an attempt to capture email addresses.

RIBA described the incident as "unusual activity" on its website and member database.

The source, traced to a Chinese organisation apparently known for large scale spamming, planted a web address.

No evidence of fraud or attempts at extracting information was found, but RIBA has warned its members to keep an eye on bank and credit cards accounts that could be used for making payments to the organisation.

RIBA immediately moved to strengthen its systems, said Richard Hastilow, chief executive.

"I greatly regret this intrusion and the concerns it may cause to members."

"We are taking urgent action to upgrade the protection of our systems against this latest type of threat’.