The newspaper said the capital injection, through Monarch's offshore holding company Petrol Jersey, was carried out in several tranches between October 2016 and March this year.
The airline's private equity owner, Greybull Capital, declined to comment on details of the financing, saying that they were "commercially confidential," the FT added.
It denied to the newspaper that there had been anything secretive about the transaction.
Last year, Monarch secured a £165mln lifeline from Greybull, enabling the airline to renew a key operating licence and fund new aircraft.
The equity investment had been agreed only hours before Monarch’s operating licence was due to expire, allowing the packaged holidays airline to keep flying.
The airline had said that the investment would fund the replacement of its Airbus jets with more fuel-efficient Boeing 737 MAX-8 aircraft between 2018 and 2021.
The low-cost carrier is the largest UK airline to go bust, affecting nearly 900,000 passengers.
Elsewhere, talks between UK discount airline easyJet PLC (LON:EZJ) and insolvent German carrier Air Berlin over the sale of up to 30 planes are at risk of falling apart, according to a report in a German newspaper.