Moscow Radio buttons a loose lip

Moscow Radio's world service is doing some soul-searching over an embarrassingly successful bid by one of its announcers to peddle his un-Soviet view on events in Afghanistan.

As a result of an in-house review of the snafu, live bulletins have been done away with, Soviet sources say. Moscow's message to the world is to be strictly prerecorded.

No one at Moscow Radio has agreed to comment to the Monitor, but other Soviet sources say the wayward announcer, one Vladimir Danchev, revealed during the investigation that his on-air ''slips'' began back in February.

His reinterpretation of the Soviet line on fighting south of the border was, the investigation reportedly showed, ''a question of personal belief. He lived in Tashkent (in Soviet Central Asia) before Moscow. . . . He told the investigators that he could understand the position of the rebels in Afghanistan.''

Mr. Danchev, who simply switched a word here and there in his news-reading to reflect Afghan resistance to Soviet ''occupation,'' might have got away with his one-man show for much longer had it not been for a helping hand from London.

The assist came from the British Broadcasting Corporation's routine monitoring of Soviet broadcasts. ''The embarrassing thing,'' a Soviet source says, ''is that the radio didn't discover the mixup itself. . . . The BBC had to tell them.''

The official Soviet line is that the United States and other ''imperialists'' started the Afghan crisis by launching an ''undeclared war'' against the Kabul regime, and that Moscow then came, reluctantly, to the rescue of the ''Afghan revolution.''

So far, the authorities seem to be going relatively easy on Danchev.Soviet sources say he has been sent back to Tashkent but apparently not detained.