Singapore’s financial regulator has returned about S$10 billion ($7.72 billion) in temporary fines imposed on 19 banks that it punished last year in a global investigation into the alleged manipulation of market benchmarks and the foreign exchange system.

Singapore’s financial regulator has returned about S$10 billion ($7.72 billion) in temporary fines imposed on 19 banks that it punished last year in a global investigation into the alleged manipulation of market benchmarks and the foreign exchange system, media reports said.

The Monetary Authority of Singapore reportedly said the lenders, including Singapore-based banks DBS, United Overseas Bank, Oversea-Chinese Banking Corp, UBS, Bank of America Merrill Lynch, Royal Bank of Scotland and Deutsche Bank, had taken sufficient action to help prevent a repeat of past failings.

The MAS reportedly said in an emailed statement: “The MAS has returned the additional statutory reserves to the 19 banks. These banks have completed the remedial actions to strengthen the governance, internal controls and surveillance systems for their benchmark submissions and trading operations.”

The action by the MAS comes after investigations in the city-state that began last year. authorities around the world have been probing claims that interbank rates such as Libor have been manipulated. Already, banks such as Barclays, UBS and Royal Bank of Scotland have been fined by UK and US authorities.

The affected banks asked to post reserves ranging from S$100 million to S$1.2 billion for a year at zero interest in June 2013.