In a darkened downtown Tehran government building at 10:30 one night this week, a young couple worked in the fourth-floor meeting room of Iran's Central Bank governor pulling documents in Persian from stacks piled on the large mahogany conference table.

They were trying to reconstruct the transfer of funds from Iran to other countries to Artizas, a construction company owned by the shah. At the other end of the table a middle-aged man matched lists of assets of the shah's Pahlavi Foundation with loan records from several Iranian banks.

The three people in the room were key analysts in what probably is one of the biggest and most complex international financial investigations ever undertaken.

If this were the United States, hundreds of FBI and Internal Revenue Service agents plus congressional committee investigators and certainly the General Accounting Office would be swarming over the banks, businesses and government agencies that handled the shah and his family's financial dealings over the past 25 years.

This, however, is revolutionary Iran and the inquiry is being handled by about 50 enthuusiastic investigators, mostly of graduate-school age, with no past investigative experience.

The director, Ali Teza Nobari, 32, is a French- and American-educated Iranian who smilingly admits to being still registered as a graduate student at Stanford University, from which he already has two master's degrees.

As governor of Iran's Central Bank, Nobari must also handle the crisis caused by the international financial struggle between Iran and the United States brought on by the seizure of American hostages in the Tehran embassy. sIn addition, as key aide to Iran's finance minister, Abol Hassan Bani-Sadr, Nobari is also helping design a plan to restructure the nation's banking system.

Publicity is an important product of the group's work. Nobari and Bani-Sadr believe the most forceful pressure on President Carter to turn over the shah for trial here would be an American public aroused by an accounting of what the former Iranian leader and his family did.

Their view, however, conflicts with that of other members of this country's revolutionary leadership who think that if Iran attacks the U.S. Embassy as a "nest of spies" and threatens trials for the hostages, Carter eventually will give in.

It is a slow operation, since many files have been destroyed and those that remain frequently have been kept in haphazard fashion. The worst destruction of records came from a fire in Bank Omran, where much of the shah's financial activities took place.

But at the Pahlavi Foundation, once the center of the shah's financial operations, filing cases, ledger books and used vouchers are piled outside the building with more being delivered by truck daily from storage areas around the city. The investigators often have been tempted to strike out after some lead that they hope might catch some longtime enemy.

Early this week, for example, they turned up a $150,000 New York bank check drawn on Iran's Bank Omran that had written on it, "Paid as per Mr. -- ", with a name the same as that of a congressman who supported the shah. Outsiders had to tell them that the notation most likely referred to the banker in Rabat, Morocco, who approved its being passed.

They are also enthusiastically gathering anything they can about the shah's relationship with Henry Kissinger and with David Rockefeller and Chase Manhattan Bank.

One avenue being pursued, they said, is a trail of checks in the 1960s from the shah through Chase to the late New York jeweler Harry Winston. These could amount to $50 million to $30 million, one investigator said.

Nobari asserted in an interview that proof has already been uncovered of "negative balances on checkng accounts, and promissory notes" left unpaid in Iranian banks when the shah and his family fled the country.

He said the total came to "about $100 million" but so far was undocumented.

The investigation's first report, due out in a few days, is to carry a summary of the Pahlavi Foundation's biggest holdings and maybe a list of companies in which the shah's participation was paid for with land expropriated from private citizens purportedly for goverment use.

Also in preparation is a list of outstanding loans made by the Pahlavi Foundation, many from banks outside Iran.