New powers allowing law enforcement and intelligence bodies to demand the communications records of British telephone and internet users may be illegal, according to legal advice given to the privacy watchdog.

Elizabeth France, the information commissioner, has told the Home Office that the new powers could breach human rights law because communucations logs available strictly for national security investigations can also be accessed by police officers for more minor cases such as public health and tax collection.

Home secretary David Blunkett has also been warned of potential legal complications with the proposed nationality, immigration and asylum bill.