International Accreditation New Zealand (IANZ) informed the local body last week that its building consent accreditation would be revoked after it failed to meet requirements.
The council officially lost its consent accreditation on Monday.
Mr Marryatt was stood down on indefinite leave last Wednesday over the consents crisis and a Crown manager was appointed.
The council's announcement comes as the Government orders an independent "diagnostic assessment'' of the council's resource management planning and resource consenting functions.
The council today welcomed the move, saying the assessment was designed to see if they were sufficiently resourced and had "suitably robust'' resource management processes in place.
It is a non-statutory assessment, and ministry staff will meet council staff and other agencies and stakeholders over the next few days to gather information.
They will then prepare a report for the minister, to be delivered in the last week of July.
The council's resource consents team operates separately from the building consent team, and does not fall under the jurisdiction of IANZ.