Part of the text by L. M. Lavrin published in the journal of Crimean Karaites, June 1998, Simferopol (text of lecture which took place in town of Troki)

Hazzan El after the overthrow of the tzarist government (in year 1917) suggested that the Karaite community of Harbin (northeast China) should accept Gentiles into their Karaite religious community, on the basis of all the principles of The Karaite faith and in compliance with all of the Karaite religious ceremonies.
He was inspired by Isaac Sangari‘s mission among the Khazars. 

The Leaders of the Karaite community led by Hazzan El after a long and deep study of  proselytism decided to accept the proposal and decided to accept two Japanese people and one Russian into their Karaite religious community.

It was the end of the validity of the Karaite statement, which stated it was impossible to become a Karaite in any other way than being born a Karaite.

From this time the new statement began to be valid, which stated that Karaites could not only be a Karaite by birth, but also by conversion.