The amended declaration for 2014 was published on the website of the Verkhovna Rada in August, Radio Liberty reported.
In March, when all MPs are requested to submit their declarations of income, Kotvytsky entered UAH 63.867 million in savings. As of now the amount has been increased by UAH 907.05 million.
The amount of total income was also increased from UAH 26.06 million to UAH 71.9 million, resulting from growth in income from dividends and interest payments.
When asked to comment on where those UAH 900 million came from, Kotvytsky told a journalist of Radio Liberty to ask a person who filled his declaration for 2014.
"This is a question the accountant should be asked. It was a typographical error. This is money that for many years has been held in bank accounts and did not appear from anywhere," he said.
It is worth noting that Kotvytsky is a business partner close to Ukraine's Interior Minister Arsen Avakov.
Before being elected to parliament, Kotvytsky was a member of the Supervisory Board - Vice-President of OJSC Investor, which specializes in providing information, advisory and marketing services, wholesale trade, as well as office space renting.
Avakov himself was Chairman of the Supervisory Board - President of Investor company until 2013, and currently this position is held by his wife Inna Avakova.
According to official data of Stock market infrastructure development agency of Ukraine, as of 2013 Inna Avakova held 42.064% of the shares of PJSC Investor, with 1.69% owned by a son Oleksandr Avakov and 9.566% - by Kotvytsky.
Since then, information about the change of ownership of Investor company was not officially disclosed.