Prosecutors filed for a court warrant Wednesday to arrest an asset manager of former President Lee Myung-bak in connection with allegations that Lee maintained a slush fund.

The Seoul Central District Prosecutors' Office said it requested a writ for Lee Byung-mo, the executive secretary of the Cheonggye Foundation on the charge of destruction of evidence. He was placed under 48-hour detention on Tuesday.

Lee is suspected of disposing of ledgers that apparently had detailed records of the ex-president's financial accounts, possibly created under borrowed names, and their transactions. Lee is known to have long worked for the former president, mainly taking care of assets and property.

Lee has been questioned by prosecutors over his involvement in and knowledge of the 26.3 billion-won ($24.4 million) proceeds the former president's family gained from the sale of a large land lot in southern Seoul in 1995.

Prosecutors suspect the proceeds actually belonged to the former president and he used the money to acquire a controlling stake in DAS, a lucrative auto parts maker. On paper, DAS is owned by his elder brother, Lee Sang-eun. Rumor has it that DAS has been a secret vault for a slush fund belonging to Lee suspected to be worth at least 12 billion won.

The former president has categorically denied the allegations.

The prosecution probe is closing in on the former conservative president, who ruled from 2009-2013, as separate investigations are also under way over DAS' suspicious recouping of its 14 billion-won investment in a US-based firm.(Yonhap)