Malaysian police seized 72 suitcases stuffed with cash and jewels along with scores of designer handbags in raids on luxury properties linked to ex-prime minister Najib Razak on Friday as a corruption probe gathered pace.

The discovery adds significantly to the peril faced by Najib, who just last week had seemed to be cruising toward an election victory, before he was unseated in a stunning upset.

A visibly shattered and anxious Najib declined to comment on the latest developments as he waded through a throng of media into a mosque for Friday afternoon prayers in the Muslim-majority country.

Asked to comment, Najib, 64, patted an AFP journalists' arm and said: "Later, later."

Police said that the sheer size of the trove of cash, jewels and 284 boxes containing Hermes, Birkin and Louis Vuitton handbags prevented them from immediately estimating the haul's value.

Extensive searches of Najib's home and several other sites began late Wednesday, making good on a pledge by the new government headed by 92-year-old Prime Minister Mahathir Mohamad to investigate the ex-leader.

Police had previously declined to comment on the raids.

But Amar Singh, head of the commercial crime investigation unit, confirmed that the latest raids on early Friday were part of investigations into accusations that Najib, his family, and cronies looted billions from a state investment fund he founded.

"I can't give an estimated value of the items," Amar told reporters at the upscale Kuala Lumpur condo complex where the latest raids were carried out.

"We have sealed the bags but we know they contain money and we know they contain jewellery."

Money bags

He said the 72 suitcases were filled with large amounts of "various currencies, including Malaysian ringgit, US dollars, watches and jewellery".

"The amount of jewellery is rather big," he said.

Footage captured by local media showed cardboard boxes and suitcases, sealed in plastic wrapping, being loaded into a black police truck. It took five trucks to remove all of the seized items, reports said.

Just last week, Najib was widely expected to lead his powerful Barisan Nasional (National Front) political machine to another victory, extending a more than six-decade reign that had made it one of the world's longest-serving governments.

But his coalition — accused of ballot-box stuffing and gerrymandering — was unexpectedly trounced by a diverse alliance that rallied public support against Najib's suspected corruption and increasingly repressive tactics.

The handbag discovery will add to public scorn for Najib's wife Rosmah Mansor, who has long been reviled by Malaysians for her perceived haughty demeanour and reported vast collection of designer bags, clothing and jewellery collected on jet-set overseas shopping trips.

Her reputation contributed to voter perceptions of rot in a ruling establishment that had lost touch with economically struggling and middle-class Malaysians.

Mahathir had already barred Najib from leaving the country in the wake of last week's election over allegations that he oversaw the looting of billions of dollars from sovereign wealth fund 1MDB in a breathtaking and complex campaign of fraud and money-laundering stretching around the world.

The police actions have fuelled speculation in Malaysia that Najib would soon be taken into custody, but so far there has been no indication that an arrest is imminent.

Mahathir and Anwar Ibrahim, the former opposition leader who was jailed under Najib but freed on Wednesday, indicated this week that they expect charges to be filed against Najib soon.