The top South Korean Central Intelligence Agency official in Washington opened personal bank accounts last fall with deposits - mostly cash - totaling more than $250,000.

The official, Chung Tae Dong, who is listed as special assistant to the Korean ambassador here, refused to comment on the purpose of the funds under his control.

An embassy spokesman also declined comment except to say that any large amounts in Chung's accounts are official, rather than personal, funds. None of the money has been spent on lobbying members of Congress, the spokesman added.

A House investigating committee has been seeking testimony from another Korean diplomat, former ambassador Kim Dong Jo, who is suspected of making cash payments to as many as 10 current House members.

Kim also kept large cash balances in personal accounts during his tenture in Washington from 1967 to 1973, investigators have found. At times he withdrew amounts as large as $5,000 in cash, which House investigators feel may have been used for payments to members of Congress.

There is no evidence that the money in Chung's accounts has been used for illegal purpose, but the mystery about the funds has now attracted the attention of House investigators.

Copies of bank records made available to The Washington Post by non-government sources show for instance, that the savings account the KCIA station chief opened last November with a $148,000 cash deposit was still largely untouched as recently as late March.

A checking account that Chung opened last Sept. 26 at the same Union First National Bank branch with a deposit of $107,656.09 has shown more activity, according to the records. It had a balance in late March of about $38,000.

The checking account was opened shortly after a KCIA official in New York sought asylum in the United States. This raises the possibility that the Koreans were transferring to Chung money that had been controlled by the defector, Sohn Ho Young.

There is no ready explanation for the source of the later $148,000 cash savings account deposit, though investigators have found it is not uncommon for the South Korean government to send large amounts of currency to its embassy through the diplomatic pouch.

A House International Relations subcommittee investigating U.S.-Korean relations has been seeking an explanation for the cash balances held by Chung, whom its investigators have identified as the top KCIA official at the embassy.

Chung, who attended Oberlin College in Ohio and received a PhD. from Georgetown University, came to Washington 14 months ago to succeed Kim Yung Hwan as station chief.

Kim Young Hwan was recalled to Seoul after newspaper revelations about South Korean eforts to lobby members of Congress with large cash gifts. His top assistant here, Kim Sang Keun, defected in late 1976 and has been a key U.S. government witness in the influence-buying investigation.

Since Chung has been in Washington, KCIA officers attached to the embassy have kept a low profile, according to federal investigators and members of the local Korean community.

A top priority for KCIA agents in this country has been keeping track of Korean-Americans critical of the regime of President Park Chung Hee.

There have been few complaints of KCIA harassment by these dissidents in the last several months, however.