The number of suspects arrested in a spiraling investigation into an investment fund scam in Türkiye has reached 45, officials said Friday.

Prosecutors are parsing the operations of 131 investment funds held by seven companies, whose assets are reportedly worth more than $18 billion.

Authorities took steps last week to support financial stability, with investigations focused on suspected share price manipulation in thinly traded stocks.

Justice Minister Akın Gürlek said Friday that prosecutors were investigating 76 suspects, of whom "45 have been arrested," he posted on the social media platform X.

Among the arrested is Erkan Kilimci, a former deputy governor of Türkiye's central bank, media reports said.

Gürlek said authorities had seized the assets of those who either owned or were involved in managing the now-liquidated investment funds, and those of their immediate family members.

The problems emerged in early September after Türkiye's Capital Markets Board (SPK) changed its guidelines for investment funds, saying they could no longer invest all their assets in one stock but were required to diversify.

The move sought to address concerns that many funds were heavily investing in a small number of obscure or hard-to-sell stocks.

To comply, funds began selling stocks, spooking investors who started trying to cash in their investments.

But a scandal erupted last week when several companies admitted they were unable to satisfy investor redemption demands.

A day later, all 131 investment funds were placed into liquidation by the SPK, which said nearly half a million individual investors were affected.

Treasury and Finance Minister Mehmet Şimşek denied the rumours that he was preparing to resign.

"The allegations circulating about my resignation are baseless," Şimşek posted on X late Thursday.

"The public should pay no heed to such speculative news intended to undermine our country's economic stability," he said.

Gürlek said investigators were pursuing their investigations to determine those responsible.

"No one is being shielded, and no one is receiving preferential treatment," he said. "Those responsible will answer before the law, and the rights of affected citizens will be fully safeguarded."

In his first comments, President Recep Tayyip Erdoğan said Thursday that those responsible will be held accountable, stressing that the liquidation of the funds posed no risk to Türkiye's financial system or the wider economy.