MANILA - The Philippines could tighten its money laundering law this year to cover casinos, its top lawmaker said on Monday, in a move aimed at plugging loopholes that allowed $81 million stolen from Bangladesh to pass through Manila gaming venues.

The Senate aims to approve its version of the bill in May and it is likely the lower house of Congress would hold separate discussions on its version around the same time, said Senate President Aquilino Pimentel.

Apart from strict enforcement of a "know-your-customer rule," casinos would, under the proposed amendment, be required to report to the country's anti-money laundering body accumulated bets within a 24-hour period totalling 3 million pesos ($60,000), he said.

The review of the existing law comes after a breach last year of Bangladesh Bank's systems and use of SWIFT messaging network to request nearly $1 billion from its account at the New York Federal Reserve in early February.

The branch of the U.S. central bank rejected most of the requests, but $81 million disappeared into casinos and other entities in the Philippines.

"The pending bill is one of the products of the (senate) investigation," Pimentel told reporters, referring to the inquiry it conducted last year into the stolen Bangladesh central bank money.

The exclusion of casinos from the current scope of the anti-money laundering laws and a strict bank secrecy law have made it difficult for authorities to track the Bangladesh money trail and identify the perpetrators.

Bangladesh's central bank has retrieved just under a fifth of the stolen funds.

The plan is for President Rodrigo Duterte to sign the measure into law this year, Pimentel said.

Duterte has expressed frustration at the country's anti-money laundering body for lack of progress in tracking the proceeds of illegal drugs trafficking, a task made more difficult by its tough bank secrecy laws.

Amending the law had been an uphill battle because of fierce lobbying by the gaming industry, according to lawmakers.

Casinos last year raked in 149 billion Philippine pesos in gross gaming revenue, data from the gaming regulator showed.

Pimentel also said the Senate would not close its doors to reopening the investigation into the heist, given that only a small amount had been recovered.

Asked whether the revelation by U.S. Federal Bureau of Investigation that North Korea was responsible could compel lawmakers to revive the probe, Pimentel said: "Allow us to process the information first."