A shakeup at the Nueces County Appraisal District is being blamed on what's being called a vindictive anonymous letter.

That anonymous letter was sent to the state office that oversees and regulates appraising certifications. It pointed out that Chief Appraiser Ronnie Canales does not meet the top-level certification that went into effect Jan. 1.

So now, Canales will be resigning.

The anonymous letter allegedly contains many accusations against Canales and his office, but the most critical accusations put his qualifications as the county's chief appraiser into question.

"I have to step down for the simple reason that we don't want to jeopardize, I don't want to jeopardize, the certification of the tax roles," Canales said.

The former Nueces County Tax Assessor-Collector, as well as former board member of the Appraisal District, said the letter sent to the state accused Canales of not being qualified to hold the position of chief appraiser -- a post he's held since 2012. The question of his qualification is based on a new rule that went into effect Jan. 1, requiring all chief appraisers to hold a certain level of certification -- a level four registered professional appraiser. Canales currently holds a level three RPA.

"I had this designation back in the 80s when I used to work here, but since I came off the appraisal district, became the tax assessor-collector, I had to park my license. Then I had to get my other license for tax assessor-collector," Canales said.

When Canales was first appointed to the board, he said he made the board aware that he was a level-three appraiser.

Canales said he would rather step down and continue to work on his re-certification than delay the distribution of the tax rolls to the 35 taxing entities who depend on the money to stay in operation. He will formerly tender his resignation to the appraisal board on Thursday.