Ayatollah Ruhollah Khomeini today banned the import of frozen meat -- which accounts for roughly a third of Iran's requirements -- on the ground that slaughter abroad failed to meet strict Islamic standards.

Coming only a day after the religious leader left Tehran for the holy city of Qom, the decision was widely interpreted as signaling that he had no intention of relinquishing effective power as some had suggested his change of residence indicated.

The decision, however, coming on the heels of other Khomeini edicts enforcing strict Islamic practice, may indeed hasten a decline in his once unquestioned leadership, already marred by persistent lay and leftist opposition to his dream of turning Iran into an Islamic republic.

Khomeini, according to the state "Voice of the Islamic Revolution" radio, also ordered all frozen neat now in Iran to be destroyed, raising the specter of meat shortages and even greater inflation.

Australia, New Zealand, France and Eastern Europe traditionally supplied most of Iran's frozen meat imports.

Meat specialists said substituting imports of live animals would inevitably cost more. At present Iran produces an estimated 500,000 tons of meat annually, but consumes 700,000.

Other recent controversial Khomeini decisions include suspension of the 1967 Family Protection Act and introduction of accelerated justice in keeping with Islamic law.

The 1967 family law, in effect, forbade polygamy and provided women protection against automatic divorce countenanced by the Koran.

In another development, an angry mob was reported by the state radio to have killed three former policemen in Najafabad near the central city of Isfahan.