Emergency measures were deemed necessary after court evidence revealed young people at the Ripple Road mosque in Barking were shown Isis videos by convicted extremist Umar Haque.
Boys at the mosque were said to ”traumatised” by the violent propaganda and role-playing training exercises.
Social services and police discovered Mr Haque had attempted to radicalise 55 children between the ages of 11 and 14 at after-school classes.
Mr Haque was jailed for life with a minimum of 25 years at the Old Bailey in March this year.
He was found to have planned gun and car bomb attacks designed to strike 30 high-profile targets in the capital - including Big Ben, the Queen’s Guard and Westfield shopping centre.
Haque also taught pupils at the fee-paying independent Lantern of Knowledge School in Leyton, where he admitted playing Isis propaganda videos.
The Charity Commission began investigating the Essex Islamic Academy charity running the mosque in October 2017.
A statutory inquiry was announced in March after Mr Haque was convicted of preparing terrorist acts while employed there.
Jonathan Burchfield of law firm Stone King was installed as manager at the charity on Thursday. He said only that he and his team “appreciate the confidence” shown in them.
The commission’s investigation is still considering how Mr Haque was able to carry out his attempted radicalisation at the mosque and what others at the charity knew about his activities.
Mr Burchfield will review the charity’s financial controls and policies, but the trustees will still look after the day-to-day running of the charity.
Michelle Russell, director of investigations, monitoring, and enforcement at the Charity Commission said Mr Haque’s crimes as “horrendous” and likely had a “devastating effect” on young people at the mosque.
She said: “This is one of the worst cases we have seen with children, as young as 11, being exposed to harm through attempted radicalisation and terrorist material by this man.”
Additional reporting by agencies
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