NEW YORK, APRIL 6: Russia has retained a clandestine offensive biological weapons capability and could return to production in ``just two or three months,'' according to a top germ warfare defector.The former scientific chief of the Soviet germ warfare programme, Kanatjan Alibekov, made the charge in an interview with AFP to coincide with the publication of his book Biohazard written with American journalist Stephen Handelman.The book by Kazakhstan-born Alibekov, who is now known as Ken Alibek, also reveals that the world's biggest single outbreak of anthrax this century, in Sverdlovsk, was caused by a failure to replace a clogged filter at a top secret biological weapons plant.Russian authorities continue to blame the March 30, 1979 incident at Sverdlovsk, which according to Alibek killed 105 people, on ``contaminated meat.''Alibek, a medical doctor with the military rank of colonel, was the top scientist in charge of the Soviet germ warfare programme from 1975-1991. He defected inJanuary 1992.Alibek worked at Biopreparat, set up in 1973 as a civilian cover for the Soviet BW (biological weapons) offensive programme.He personally directed concealment efforts from 1988, aimed at hiding the programme from the world which outlawed biological weapons in a 1972 treaty signed by his country.He points to published reports in Russian scientific journals to affirm that despite a decree by Russian President Boris Yeltsin in 1991, which banned offensive biological warfare research, Russia continues to retain BW capability.``For Biopreparat, it would take just two or three months to be fully prepared for production of BW,'' he says.