An investigation by South Korea's human rights watchdog found no evidence the country's spy agency tricked or coerced a dozen North Korean restaurant workers into defecting in 2016, as some have alleged, documents reviewed by Reuters showed on Tuesday.

Lawyers for some of the women said they would seek to challenge the findings in court, setting up a potential legal fight over a saga that has complicated efforts to improve relations between the two Koreas.

The group's defection was one of the largest known cases of its kind, and the South Korean government's decision to publicize it broke with long-held practice that it does not identify defectors on safety and privacy grounds.