The Internal Revenue Service has known of people who were dealing in hundreds of thousands of dollars in cash who did not file tax returns, but has often ignored these cases, said Sen. David H. Pryor (D-Ark.), chairman of a congressional IRS oversight subcommittee. “The IRS has their addresses and yet no one from this Administration so much as knocked on their door,” Pryor said in a Senate floor speech. Pryor, who said he plans to hold a Senate hearing next year on the inaction, said an IRS internal report he obtained shows the agency learned of 244 people who had cash dealings over $100,000 but filed no return. The agency pursued only 47 of the cases, he said. An IRS spokesman said the report was based on 1982 tax returns, and that since then the agency has developed an improved computer system for using bank transaction records to target tax cheats for investigation.