The District's finance and revenue director and his chief property tax assessor yesterday denied allegations that they had arbitrarily excluded portions of the city's most expensive commercial propoerty from reassessments last year, and that they had lied to a Superior COurt judge.

At a City Council budget hearing yesterday, Kenneth Back, director fof the Department of Finance and Revenue, said that D.C. auditors Matthew Watson and Carl Bergman were "misin-formed" when they asserted in a recent report tha the city tax officials failed to reassess about 147 properties, most of them commercial, in downtown Washington.

"The D.C. auditor doesn't know what he is talking about," Back said. "The whole issue is whether these properties were reassessed or not and our position is that they were. They are going along picking up a few of the over 3,000 properties that we have to assess and because a few of the assessments were not changed, they are saying that they were not reassessed."

Bergman charged that the alleged failure to reassess the properties involved cost the city about $2 million in lost taxes and that tax officials lied to a Superior Court judge when they said that all property had been reassessed in a certain section of the city. That section is bounded by Rock Creek Park, Massachusetts and Pennsylvania Avenues and 15th Street NW.

A Washington couple, Tom and Marguerite Kelly, sued the city about three years ago, asserting that tax assessorts were working haphazardly in revaluing some properties and ignoring others.

A D.C. Superior COurt judge supported the Kellys. But city officials complained that they did not have enough tax assessors to reassess each piece of property annually. The judge, John Garrett Penn, subsequently ordered the city divided into two areas, each of which would be inspected and reassessed, if necessary, every two years.

But a 1975 congressional action required tax assessors to reassess property annually. When the city complied in 1976, a Superior Court judge found that some property had been reassessed unfairly, and ordered that these assessments be rolled back to the 1975 level.

It is that action that has become a point of contention between the tax assessors and the D.C. auditors.

The auditors said that when they examined the records of tax assessments, they found that some records of assessments made by "junior property tax assessors" had been erased.

Back countered that there was not enough information that would justify what he called the preliminary reassessment made by teh "junior assessors" and that a supervisor had decided that those assessments would not be changed.