Video report by ITV News Political Correspondent Daniel Hewitt
Students set to receive their BTEC results on Thursday will no longer do so after a change in the system less than 24 hours before grades were due out.
Schools and colleges have been told not to issue the results of the vocational and technical qualification following a last-minute U-turn on grading.
Exam board Pearson wrote to education leaders expressing concerns about "unfairness" in the system in light of the government's similar 11th hour U-turn on A-level grades last week.
On Wednesday, schools and colleges received an email advising their student's BTEC grades would be "reviewed and where appropriate, regraded".
Pearson said it would work "urgently" to get the grades out to young people, but did not but a timescale on when that might happen.
In the email, Pearson's Senior Vice President Cindy Rampersaud wrote: "Our priority is to ensure fair outcomes for BTEC students in relation to A Levels and GCSEs and that no BTEC student is disadvantaged".
ITV News reported on Tuesday about fairness concerns in the system, as officials warned BTEC students could be "squeezed out" by inconsistencies in grading approaches.
But Pearson said at the time that only a "very small number of grades" had been adjusted through the controversial algorithm, and these would be reviewed on a "case by case basis".
But Wednesday's announcement has asked no grades be issued on Thursday so that the awarding body can "recalculate the final grades."
'I'm just baffled' BTEC student Bijaya Tamang told ITV News on Tuesday after he and others were initially left out of the grading system changes:
In light of Wednesday's 11th hour changes, a spokesperson for Pearson said: "Following Ofqual’s announcement that A-level and GCSE students are to receive centre-assessed grades, we will be applying the same principles for students receiving BTEC results this summer.
"We will be regrading BTECs to address concerns about unfairness in relation to A-levels and GCSEs and ensure no BTEC student is disadvantaged."
She added: "We know this could cause additional uncertainty for students and we are sorry about this.
"Our priority is to ensure fair outcomes for BTEC students and we will work around the clock to provide revised grades as soon as we can."
On the latest announcement, Shadow Secretary of State for Education, Labour's Kate Green said: "This latest chaos is totally unacceptable."
She added: "For some young people to find out less than a day in advance that they will not be receiving their grades tomorrow is utterly disgraceful".
A Department for Education spokesperson has previously said: "Our priority is to ensure all students are treated fairly, including those who received vocational and technical results last week, such as BTECs and Cambridge Technicals."