These six boxes of Sats papers were left unmarked in a Lancashire school
Head teachers say they warned officials of potential problems with England's Sats marking system months before the chaos hit the headlines.
The head of the Lancaster Road Primary School, in Morecambe, Paul Gabriel, said he had contacted the Department for Children, Schools and Families when the Sats packs arrived to warn that the system being put in place was far too complicated.
The claim comes as Lord Sutherland's inquiry into the testing "shambles" laid blame at the door of both the private contractor ETS and exams watchdog the Qualifications and Curriculum Authority (QCA).
He also said that there were warnings of problems as early as July 2007.
Mr Gabriel said he himself had attempted to warn the Children's Secretary Ed Balls through officials at his department of likely problems.
"We were telling him there were problems long before we got to the marking stage," he added.
Ministers had not acted as decisively as they had claimed, he added.
Mr Gabriel's concerns were not acted upon and half of the school's science Sats results went missing.
Pupils had to wait until after the September term began before they got their results. They had already left and gone on to their respective secondary schools.
Fellow head teacher Carolyn Clarke, of Harrison Primary School in Fareham, Hampshire, said children did not need this sort of confusion when they were about to go on to new secondary schools.
Half of her school's test results had been returned unmarked right at the end of the summer term.
But she said she had warned Ed Balls in a letter about the problems the US education system had experienced with ETS long before this happened.
"Many of us warned that ETS wasn't the right company and that it was going to go wrong."
Lord Sutherland's report says the procurement process by which ETS was given the Sats contract had been sound.
But he said the process of "due diligence", checking on ETS' references and financial strength, had failed to identify a string of press reports highlighting previous problems in the United States.
Ms Clarke said she was glad that the QCA had now suspended its chief executive Dr Ken Boston and another senior executive.
She added: "The real issue for the heads that I work with is that there are far better system than Sats to assess children.
"They wouldn't have to have this mammoth industry to mark test if they relied on teacher assessment."
The National Union of Teachers said it was unhappy with the narrow focus of Lord Sutherland's inquiry.
Acting general secretary Christine Blower said: "Sutherland has stuck like glue to his narrow remit.
"Nothing from the headline recommendations indicates his opinion of whether the test system is sustainable or right for schools.
"The fact that it simply seeks to improve the operation of a conceptually flawed system makes it only of passing interest."
John Dunford, head of the Association of School and College Leaders, said he was pleased that the power to regulate testing system was to pass to a wholly independent body.
He added: "The decision to abolish national curriculum tests for 14-year-olds has halved the size of the testing system, making it more manageable and opening the way for longer-term reform of school assessment and external testing.
"Now we have the opportunity to move the debate forward from the often sterile arguments of the last 20 years to the essential question of how assessment and examinations can best support learning.
"Assessment should not be locked into an antiquated notion of timed pen-and-paper tests as the only legitimate approach."
General Secretary of the National Association of Head Teachers Mick Brookes said: "We appreciate that since the summer arrangements have been put in place to address the logistical problems.
"However, until deeper systemic issues are tackled we will still have to operate a system that does more to damage educational outcomes for children than promote them."