PARIS (AP) _ The crippled Iranian tanker Khark 5 may again be leaking crude oil off the Cape Verde Islands in ''a serious manner,'' said a statement released Thursday by the Environment Ministry.

Attempts to transfer 53 million gallons of oil remaining on the Khark 5 to another tanker are threatened by rough seas near its position off West Africa, the statement said. The ministry listed no source of information and there was no independent confirmation late Thursday from other countries of a leak.

The Dutch salvage company Smit Tak, which is heading operations to save the ship and shift its cargo of crude to the Iranian tanker Shir Khooh, has consistently said all leaking has stopped.

The Khark 5 lost 19 million gallons of Iranian light crude after a Dec. 19 explosion ripped a hole in the vessel's hull. Before drifting seaward, the resulting oil slick threatened Morocco's fisheries and beaches but authorities said warm offshore waters helped break up virtually all of the slick.

Smit Tak hopes to transfer the remaining oil in international waters about 300 miles from the Cape Verde Islands. After the blast, Spain, Portugal, Morocco and Cape Verde barred the Khark 5 from entering their 200-mile territorial waters for fear of pollution.

Rough winter weather has prevented the salvors from beginning the three-day pumping operation.

The explosion, which occurred in stormy weather 400 miles north of Las Palmas in the Canary Islands, began a fire that forced the Khark 5's crew to abandon ship. Nobody was injured in the incident, the cause of which has not been determined.