If user demand for the 1901 census website hits previous launch levels of 30 million hits a day when it finally relaunches, it will not be able to cope.

The Public Record Office (PRO) site at www.census.pro.gov.uk is currently offline undergoing technical improvements after it failed to cope with unprecedented demand when it launched on 2 January.

The site was designed for an average of 1.2 million hits a day but received an average of 1.2 million hits every hour instead.

If the demand is repeated, disappointed users will be diverted to a static offline site where they will be forced to wait for demand to drop before being able to regain access to the dynamic site.

A spokeswoman for Qinetiq, the government-owned company behind the site, which is currently looking for a strategic partner, told vnunet.com: "The site was not designed to cope with 30 million hits a day.

"If it happens again it would not crash, but the excess number of people would be diverted to a static offline site where they would not be able to concurrently use the database."

"It would not be economic to make the site cope with such a high level of demand. The system was built to provide information to users at an affordable price based on normal levels of use with some margin built it.

"The site met PRO specifications when it first launched, but the severe overload was phenomenal.

"We understood the attraction of genealogy, but the reaction was unprecedented. We have been working around the clock to get it back up. Everyone was desperately disappointed by the fact that it didn't work."

Asked about how many users the site will be able to handle after its enhancements, the spokeswoman said: "A number of initiatives are taking place to make the site more robust, but while it is still being tested it would be premature to talk about numbers."

The site will undergo a controlled launch making it available at designated service centres in England and Wales after the improvements have been made by Qinetiq and its contractor partner, BT Ignite.

A PRO spokeswoman stated: "We don't expect the same levels of demand as when it first launched. A lot of people knew it would be made available on 2 January. We will certainly be keeping a lower profile this time."

A spokeswoman for BT Ignite refused to comment, saying that it was only the hosting company.