Rosmah Mansor, the wife of former Malaysian prime minister Najib Razak, was arrested on Wednesday afternoon in relation to the multibillion-dollar 1MDB scandal, the country’s anti-graft agency has said.

The arrest of Rosmah – long compared with Imelda Marcos, the spouse of the corruption-tainted late Philippine dictator Ferdinand Marcos, because of their extravagant spending habits – signalled that prosecutors were intensifying their months-long investigation into the scandal.

Latest: Rosmah Mansor, wife of Najib, charged with money-laundering

The Malaysian Anti-Corruption Commission said in a statement that Rosmah was arrested at 3.20pm at its offices in the administrative capital Putrajaya.

She had reported to the anti-graft agency earlier this morning for her second round of questioning in two weeks.

The agency said Rosmah would be charged on Thursday under the country’s Anti-Money Laundering, Anti-Terrorism Financing and Proceeds of Unlawful Activities Act.

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Investigations have centred on her role in the 1MDB scandal, for which her deposed husband, Najib, is also facing criminal charges that could see him spend the rest of his life behind bars if convicted.

Bags of jewellery, cash and luxury purses seized from Najib’s properties in June – soon after his shock election defeat to Prime Minister Mahathir Mohamad – were valued at some US$273 million. Among the items were Hermés Birkin bags worth upwards of US$100,000 each.

Najib said soon after the seizure that the items were mostly “gifts” given to Rosmah and his daughter.

Observers say a key reason for Najib’s defeat was widespread public opinion that he and Rosmah did in fact plunder 1MDB, as alleged by The Wall Street Journal and the investigative news blog Sarawak Report.

The US Department of Justice believes some US$4.5 billion was stolen from the state fund, set up by Najib in 2009.

Wednesday’s arrest comes amid a public groundswell for attorney general Tommy Thomas to move more quickly in investigating the scandal.

Najib Razak charged with money laundering as 1MDB case deepens

Thomas and Mahathir have said the inquiry was moving more slowly than expected because it involved tracing funds that had traversed multiple jurisdictions, including Singapore, Switzerland and the United States.

Online, many Malaysians reacted with glee over the news of Rosmah’s arrest.

“I think I will take leave tomorrow and celebrate. This is better than winning the Thomas Cup,” wrote Shahrina Kumari on the Facebook page of The Star newspaper.

Others urged authorities to impose a high bail amount for the former prime minister’s wife.

“Please don’t insult her with a [RM3 million to RM5 million] bail. Something like [RM30 million to RM50 million] will be more appropriate to match her status,” commented Chan Tuck Chen on the Malaysiakini news portal.

Najib, awaiting trial in February, is out on bail of RM4.5 million (US$1.09 million).

He faces a total of 32 criminal charges for abuse of power, criminal breach of trust, money laundering and corruption.