Oscar winner Lupita Nyong'o's family was forced to hide out in safe houses and were constantly harassed because of her father's dedication to promoting democracy in their native Kenya.

The actress, who wowed critics and audiences in her Academy Award-winning turn in 12 Years a Slave, has regularly mentioned her uncle on the awards season circuit, dedicating her Critics' Choice Movie Awards Best Supporting Actress win to her late relative.

It soon emerged that Nyong'o's beloved uncle Charles disappeared in 1980. It is believed he was murdered due to his opposition to then Kenyan President Daniel arap Moi's regime.

Now the actress' father, politician and academic Peter Anyang' Nyong'o, has revealed for the first time the extent of the threats and harassment he and his family came under for his support of an underground democratic party.

Upon their return to the African country in 1987 after several years in exile in Mexico, the family had to constantly move to ensure their safety.

Nyong'o explains, "It was a very insecure time. We were moving from one place to another, which was not good for Lupita and (her brother) Peter Jr.

"I was being picked up (arrested) monthly and weekly. It would depend on the period. It was as often as they wanted. It was mainly psychological for me, although it was physical for others. You could not wash for days, you were harassed, threatened, you couldn't sleep and it becomes unbearable.

"We were traumatised. The children were too young to understand, and it would not have been advisable to explain because you could be causing them unnecessary trauma."