Money has allegedly been stolen from a flat in Grenfell Tower, the Metropolitan Police said.
The cash is believed to have been taken after June 20 and the theft was reported on September 8.
Police refused to say how much money was reportedly taken.
A Met spokesman said: "An investigation into the alleged theft is now being carried out.
"Steps have been taken to review the security of all the flats within Grenfell Tower and some changes immediately put into place."
At least 80 people died and hundreds more were left homeless when flames engulfed the 24-storey block on June 14.