Newly disclosed court documents suggest Ofsted inspectors who wrote a damning report on Haringey children's services were ordered to delete emails relating to Baby Peter and the council, a high court judge disclosed today.

Mr Justice Foskett demanded an urgent explanation of a handwritten note found among hundreds of pages of evidence handed in by the watchdog at the 11th hour of its legal battle with the sacked children's services director Sharon Shoesmith. Shoesmith this week launched fresh legal proceedings against Haringey, Ofsted and the children's secretary, Ed Balls, under the Human Rights Act, seeking damages of more than £300,000.

"If anything like this was said and/or acted upon it could potentially raise a number of serious issues," the judge said.

The note seemed to suggest that officials sent in to the north London borough were told at a meeting soon after they began the task to delete "from the system" emails relating to "Baby P or Haringey".

"This is a matter that, in the context of this case, requires a full and proper response ... doubtless they will regard it is something to be addressed urgently," the judge said.

Shoesmith claims the inspectors' report, which led to her removal by Balls, was unfair and breached the rules of natural justice.

Ofsted has already had to apologise for what it called the "serious and deeply regrettable" mistake of failing to disclose potential evidence in the case brought by Shoesmith over her sacking.

Foskett, who described the late emergence of the documents as "very unsatisfactory", also revealed that Ofsted had disclosed even more extra evidence. His comments came in an interim ruling on an attempt by the Guardian and other newspapers to get the new evidence released.

He cautioned that Ofsted had not yet had a chance to respond to the issue of the note, saying there could be a "wholly innocent" explanation. Many emails concering Baby P and Haringey had already been disclosed, he added.

Ofsted said in a statement: "As the judge's ruling is interim, and these are matters before the court and between the parties, it would not be appropriate to comment at this time. We will be responding in full to the court on all the matters raised."

Sweeping reforms were announced today to lift the morale and status of social workers, who have come under intense criticism since the Baby Peter case a year ago. Proposals from the social work taskforce included moves to reform pay to keep top staff in frontline practice, and to improve the quality of social work degrees and the calibre of new recruits.

Social workers will for the first time need a licence to practise, to be granted after newly qualified recruits have worked a year-long probation period.