Rosmah Mansor, the wife of former premier Najib Abdul Razak, was questioned for about 13 hours at the MACC headquarters in Putrajaya yesterday.

However, her ordeal is far from over as she is scheduled to be interviewed by the police next.

According to deputy inspector-general of police Noor Rashid Ibrahim, this is over the jewellery items seized from residences linked to Najib.

"Rosmah will be called again, as the seized jewellery pieces are alleged to be hers.

"We will need her to identify and confirm the items. It is expected to be a long process, as there are many items and we need to trace them back to the seller," he was quoted as saying by Star Online.

On June 27, federal commercial crimes investigation department (CCID) chief Amar Singh revealed that the cash and valuables seized were valued at more than RM1 billion.

He said it took the police 16 days to estimate the value of the jewellery items.

The police had seized 25 bags containing 12,000 items of jewellery, including rings and diamond earrings estimated to cost RM440 million in materials alone.

Amar said these included 1,400 chains, 2,200 rings, 2,800 pairs of earrings and 14 tiaras. The most valuable piece of jewellery was a white diamond necklace estimated to cost RM6.4 million.

In a exclusive report yesterday, Malaysiakini revealed that a Dubai-based jeweller had written a letter to the CCID seeking the return of items worth more than US$5million, which were purportedly hand delivered to Rosmah.

The items from Adi Hasan AlFardan Jewellery (AlFardan) included a necklace comprising 56 heart-shaped “fancy yellow diamonds”, with the biggest stone weighing 10.7 carats. The necklace also comprises 78 other smaller regular-coloured diamonds.

Along with the alterations allegedly requested by Rosmah, it is worth US$2.248 million.

Apart from this, the jeweller also claimed to have delivered a necklace-and-earrings set, which also consisted of yellow diamonds, worth a total of US$3 million.

This necklace was made up of a string of “cushion cut” diamonds amounting to 112.94 carats whereas the earrings, also fashioned in a “cushion cut” manner, weighed a total of 17.84 carats.

According to the Gemological Institute of America (GIA), yellow diamonds are extremely precious and rare, only to be found in the Zimmi mine in Sierra Leone.

In June, Malaysiakini, in another exclusive, reported that Lebanese-based Global Royalty Trading had filed a suit against Rosmah over 44 pieces of jewellery comprising a tiara, diamond necklaces, rings, bracelets and earrings.

Global Royalty claimed that while Rosmah had acknowledged receipt of the consignment in writing, the items were no longer in her custody.