Committee leader Yasser Abul-Fotouh announced Wednesday that the committee had seized all assets of the Islamic Medical Foundation, the Brotherhood's largest charity organization, which had provided low-cost medical services at 28 branches across Egypt.
He also said that Ali Gomaa, Egypt's former grand mufti, had been appointed chairman of the organization's new board.
"The seizure and the new leadership will not affect employees or patients in any way," Abul-Fotouh asserted.
According to a Brotherhood source, the group's lawyers plan to lodge a legal appeal against the move.
The Egyptian government froze the assets of 1,054 Brotherhood-linked NGOs and 137 schools following a September 2013 court order banning the activities of the decades-old group, of which former President Mohamed Morsi – ousted by the army in mid-2013 – is a leader.
The court had also ordered the group's dissolution and the confiscation of its offices and funds.
Following the ruling, the government formed a committee tasked with managing the group's assets.
In December of 2013, the government declared the Brotherhood a "terrorist" group, blaming it for a spate of deadly attacks on security personnel.
The Brotherhood, for its part, has repeatedly denied the accusations.