Caretaker Education Minister Chaturon Chaisang said the 19,000 marks would be entered into the existing database of results for 330,000 students.

He said the one-day postponement would not affect the admission period, which takes place from today until Sunday, for university selection. After today's announcement any student complaints will be handled by 12 admission centres nationwide.

Prateep Chankong, acting director of the National Institute of Education Testing Service (NIETS), said the 19,000 sheets had been abandoned at the Sanam Jan campus of Silpakorn University in Nakhon Pathom because of communication problems between NIETS officials and staff who supervised the tests in late February.

The 12th graders awaiting the results were surprised to see a statement on the NIETS website yesterday saying the announcement had been postponed yet again.

Chaturon called an urgent meeting of education bosses who agreed to the one-day postponement.

"If we can simply delay the results for another few hours we can ensure accurate results for all students. Postponing the announcement for another day seems to be the best option," Chaturon said.

Deans of medical schools at state universities said they would take additional students if they had higher scores than those already admitted.

However, a final decision on whether this will be allowed depends on a formal announcement by the Medical Institutes of Thailand, which oversees the Kingdom's medical schools.

Dr Kamolphan Cheewaphansri, head of the parents' network, called on the Commission on Higher Education to ask state universities to admit students with high grade point averages regardless of their O-Net or A-Net scores to help those whose tests had been marked incorrectly by NIETS.

She said many students would submit a petition at Government House tomorrow asking that the original entrance examinations be used instead of the problematic O-Net and A-Net system.