Sin Kim-dan

Sin Kim-dan or Shin Keum-dan (Korean: 신금단; romanised Sin Kim Dan in English in the 1960s) (born 3 July 1938[1]) is a North Korean former track and field athlete who competed in the 1960s in the women's 200 m, 400 m and 800 m, setting disputed world records in the latter two events.

[6] She won the 400 m at the Brothers Znamensky Memorial meeting in Lenin Stadium, Moscow, in 1961, 62, and 63.

[9][10] A note in the 1964 British Athletics yearbook states, "The IAAF are withholding recognition of a time of 53.1 by Betty Cuthbert on 11.3.63 pending investigation of Sin Kim Dan's 51.9; meanwhile there is no official world record.

[3][15] Sin was reunited with her father at Haneda Airport for a few minutes before being turned back from Japan.

[16] In 1966, Time magazine stated in an article on the introduction of gender verification in sports:[17] This claim has been repeated since.