While Americans celebrate the return of their 52 countrymen held hostage in Iran for 14 1/2 months, the British government and the Church of England are still trying to win the release of four Britons imprisoned there since last August.

Three Anglican church workers -- missionaries John and Audrey Coleman and Jean Waddell, former secretary to the Anglican bishop of Iran -- were jailed in Tehran along with British businessman Andrew Pyke shortly after dozens of Iranian students were arrested here during a violent demonstration outside the American Embassy. The arrested students have since been deported to Iran.

British efforts to secure the release of the four have been led by the archbishop of Canterbury, Robert Runcie, whose executive assistant on international affairs, Terry Waite, was allowed to visit the three missionaries shortly after Christmas. He found them in good condition and was told by Iranian officials and religious leaders that they might be released "soon."

But there has been no progress since then, and Archbishop Runcie said today he is worried that "the flak flying around in the aftermath" of the release of the American hostages and the angry charges of their mistreatment might make it more difficult to free the Britons. In his appeals to Iran, Runcie has been trying to keep their case separate from the American hostages and diplomatic conflict between Britain and Iran.

"We have been well-received in contacts made on religious and humanitarian grounds" to Iran's Ayatollah Ruhollah Khomeini as "one religious leader to another," Runcie said. "We are trying to keep it on that level and make clear that the Anglican Church is not a threat to Iran. But it is beginning to get confused with political and diplomatic exchanges."

Runcie, British diplomats and Iranian officials have publicly insisted that the Britons are not being held hostage to be bartered for something Iran might seek from Britain.

But Iranian officials said Britain has inquired through the Swedish Embassy, which represents Britain in Tehran, whether the case has anything to do with the continuing pretrial detention here of two other Iranians arrested after the explosion in a London hotel room of a bomb that investigators believe was being made for an attack on the Iraqi Embassy.

While Britain has joined other members of the European Community in removing economic sanctions against Iran following the release of the American hostages, it is refusing to resume military sales at least until the four Britons are freed. Now involved in a war with Iraq, Iran badly needs spare parts for its British-made Chieftain tanks and Rapier missiles, as well as a ship made here for the Iranian Navy but embargoed from delivery. a

After the American hostages were released this week, Britain's deputy foreign minister, Douglas Hurd, called the Iranian charge d'affairs, Seyfollah Ehdaie, to the Foreign Office to ask about the four Britons. Ehdaie said afterward he hoped there would be news about them from Tehran "soon."

Waite, Archbishop Runcie's special envoy, said today that during his trip to Iran at end of last year, he won the agreement of Iranian officials that "documents that had been circulated linking [the missionaries] to various intelligence agencies," including the Central Intelligence Agency, "were ridiculous forgeries." He said the documents, replete with language errors, purportedly conveyed the CIA's "thanks" to the missionaries for giving the agency aerial photos of Iran and stated that they were paid millions of dollars.

But the documents "could sway ordinary Iranian peasants," Waite said, "and there seems to have been a groundswell against the release" of the four Britons. The fourth, Pyke, who worked for a Western helicopter survey firm in Iran, reportedly is suspected of helping people escape from postrevolutionary Iran.