John MacDonald, of Kirkin-tilloch High, was criticised by HMIE in January for the haste with which the school had introduced the early presentation of pupils in Standard grade in S3 instead of S4.
Despite revoking the scheme, the school came under fire from inspectors who checked on progress last month. The TESS believes the issue has been a growing source of tension between Mr MacDonald and East Dunbar-tonshire Council, which carried out an inspection in January before HMIE's return visit.
It is believed the local authority moved to suspend Mr MacDonald last Thursday, after the HMIE's draft report, as yet not finalised, matched the findings of their own inspection team. The report is due to be published in May.
East Dunbartonshire has declined to reveal the reasons for the suspension.
Those close to the situation are said to be shocked at the speed and harshness of the action and one source said it was believed more lay behind the suspension.
The initial inspection of Kirkintilloch High found the overall quality of the curriculum was weak, while pupils' attainment from S1 to S6 was said to range from weak to adequate.
The inspectors said the timescale for implementation had been too short, with the decision being made halfway through the previous session.
The changes in exam presentation have neither improved nor led to any deterioration in the school's Standard grade performance: in the past four years, the proportion of pupils achieving five or more Credit passes has remained the same, at around 8 per cent below the national average.
Despite the criticisms, Mr MacDonald was praised as having had a positive influence in his 18 months in the job. Leadership of the school was described by the inspectors as good, and most staff thought the school was well-led.