In spite of government moves to tighten data security in the public sector, there is still much to be done, according to the information commissioner.

"Data security matters are being taken much more seriously," said Richard Thomas, "there will soon be much more accountability within the public sector."

Speaking at Infosec conference, the information commissioner said that the head of the civil service Sir Gus O'Donnell's report into the HM Revenue and Customs (HMRC) breach would be published shortly, and contains encouraging new regulatory guidance and advice on avoiding future breaches of a similar magnitude.

"There will be an increasing emphasis on data minimisation" continued Thomas, "in instances such as the MOD laptop loss, questions such as why was such detailed data on so many people kept for so long will become as important as asking how the laptop came to be unencrypted and stolen from the back of a car."

He continued to welcome new legislation allowing the ICO to conduct unannounced spot checks on data controllers in Whitehall, and announced that Prime Minister Gordon Brown was to announce similar measures for the rest of the public sector, and possibly private companies also. "We will be conducting spot checks in Whitehall departments next year", said Thomas.

In addition, new legislation within the Criminal Justice Bill currently before the Lords will make a criminal offence of identity theft, a key step in the battle against online organised crime.

Personal data has been lost at least 94 times since the HMRC breach last year, according to a report from the ICO office yesterday. Government departments were responsible for more than two-thirds of these losses (62).

The shadow justice secretary Nick Herbert responded to the report by accusing the government of not caring about people's personal information: "It's about time for ministers to get serious about personal information" he said.

Last November 25million child benefit claimants' details were mislaid by HMRC in one of the biggest data breaches of recent years.