KUALA LUMPUR, Malaysia — The police investigating Malaysia’s former prime minister, Najib Razak, said they seized more than 350 boxes and bags containing cash, jewelry and designer handbags early Friday during searches of three residences.

Included in the haul were 284 boxes of handbags and 72 pieces of luggage containing cash, jewelry, watches and other valuables, said Amar Singh, chief of the police commercial crimes unit.

He said that the police needed to assess the seized items before they could put a value on the haul. But the amount of jewelry, he said, “is rather big.”

Mr. Najib and his wife, Rosmah Mansor, are at the center of a scandal over an estimated $7.5 billion that went missing from a government investment fund, 1Malyasia Development Berhad, which he oversaw. Authorities say that $731 million from the fund was deposited in Mr. Najib’s personal bank account.