Hiroshi Nakai, a former state minister in charge of the abduction issue, asserted Thursday that at least three or four Japanese kidnapped by North Korea are "certainly" alive.

The abductees Nakai referred to on a TV Asahi program are apparently in addition to the 12 Japanese officially recognized as abductees by the government.

He said the information was obtained during Japan's investigations into the abductions. He did not provide the names of the individuals.

Nakai said he held secret talks four times with Song Il Ho, North Korea's ambassador for normalization talks with Japan, in China and Singapore after September 2010.

Japan's official list of nationals abducted in the 1970s and 1980s totals 17, of whom five were repatriated to Japan in 2002.

North Korea maintains the abduction issue has been resolved, but the matter remains a key stumbling block in the two nations developing normal diplomatic relations.

Nakai quoted Song as saying there are "more than 200" survivors among Japanese women who moved to North Korea with their Korean husbands under a repatriation program that ran from 1959 to 1984.

Nakai was abduction minister while the Democratic Party of Japan was in power. He did not run in the general election last year and retired from politics.