Rostenkowski Stamp Purchases Probed : Congress: His office spent $17,000 in six years. Grand jury is investigating possible money laundering through House post office.

House Ways and Means Committee Chairman Dan Rostenkowski’s office spent more than $17,000 for postage stamps from the House post office during a six-year period under scrutiny by a federal grand jury, House records showed Friday.

Federal prosecutors are investigating to see whether House members converted federal funds intended for operation of their congressional offices into cash for personal use. Specifically, investigators are trying to determine if lawmakers, in effect, laundered the money by buying stamps with office funds and then selling them to the House post office and pocketing the cash.

Rostenkowski, whose office vouchers have been subpoenaed by U.S. prosecutors, bought far more stamps than other House members whose office accounts were reviewed by The Times in a random sampling Friday.

In addition, his office sometimes bought large amounts of stamps at a time--$3,000 worth of 25-cent stamps on one occasion and $2,800 worth on another--that were far above the one-time purchases by other members whose records were reviewed by The Times.

Most mailings from congressional offices use the franking privilege, which allows official mail to be sent without postage. There are times when stamps must be used, such as for overseas or personal mail.

Rostenkowski was not available for comment, but a spokesman said the congressman’s office spent an average of about $10 a day if spread over a six-year period. “I guess he bought more stamps than other people,” he said.

In a statement issued earlier, the 17-term Chicago Democrat, who is a pillar of the House Democratic leadership, promised to cooperate with the investigation.

“Like many people, I am interested in learning what this is all about,” the statement said. “As for the subpoena for my records, the U.S. attorney was required to pursue a subpoena to request the documents he seeks because House members are barred from voluntarily providing such information.”

Two other House members whose records also were subpoenaed--Rep. Austin J. Murphy (D-Pa.) and Rep. Joe Kolter (D-Pa.)--also reported large stamp purchases during the period from 1986 through 1991.

Kolter bought more than $12,000 worth of stamps in that time, including two buys of $2,000 each, while Murphy’s records showed he spent more than $6,500 for stamps from the House post office in the period being examined by the office of U.S. Atty. Jay B. Stephens.

Documents filed with the House clerk indicated that Rostenkowski’s office bought stamps in four-figure batches at least once in every year from 1986-90, but reduced its 1991 postage purchases at the House facility to $696.

There also was a repeated pattern of a large purchase of stamps followed shortly afterward by a $100 purchase. For example, his office spent $3,000 on stamps on March 17, 1988, but then bought another $100 worth on March 31 of that year.

The same pattern was repeated in 1989, when a $2,300 stamp buy on April 26 was followed on May 4 by a $100 purchase. Similarly, Rostenkowski’s office spent $2,100 for 9,545 22-cent stamps on Aug. 7, 1986, and then bought an additional $100 worth of postage 18 days later.

Over the six years, his office made a total of 16 stamp purchases in $100 batches, indicating that was a standard procedure.

Illegal conversion of office funds would subject members to prosecution for violation of income tax and fraud laws.