Angus Miskers - you do not know this and have no proof of it.  Please read the following articles to get a taste of what Magnitsky was all about.

https://consortiumnews.com/2017/07/13/how-russia-gate-met-the-magnitsky-myth/

https://consortiumnews.com/2016/06/21/destroying-the-magnitsky-myth/

https://consortiumnews.com/2016/04/29/no-dissent-from-anti-russian-propaganda/