MANILA, Philippines—Former First Lady Imelda Marcos and her daughter Imee are to testify before the Sandiganbayan on Monday to support government claims that the bulk of tycoon Lucio Tan's corporate holdings belong to the late dictator Ferdinand Marcos.

The Sandiganbayan’s Fifth Division on Friday issued summonses to the Marcoses and their former financial manager, Rolando Gapud, who is now based in Hong Kong, as requested by the Presidential Commission on Good Governance.

The testimony of the Marcoses is expected to support efforts of the government to recover the supposed ill-gotten wealth amassed by Tan, who allegedly had been a close business partner of the late president.

The PCGG asked the court to summon the former first lady, her daughter and Gapud to support the testimony of Ilocos Norte Representative Ferdinand "Bongbong" Marcos Jr., who claimed in August last year that 60 percent of Tan's corporate holdings belonged to his father.

The young Marcos presented photocopies of a deed of assignment illustrating how the assets of his father and Tan were put under Shareholdings Inc., a holding company for all the companies now controlled by Tan.

He also claimed that the businessman promised to help him learn how to run the businesses and even gave him a tour of some of these companies.

The former first lady was subpoenaed twice in June but failed to appear, with the first summons sent to the wrong address. She had to postpone her appearance on June 4 because she was sick.

The PCGG was expecting the former first lady to bring with her original papers proving her son's claims.

Some of these documents, as the PCGG had earlier elaborated, pertained to Silangan Holdings, Foremost Farms, Inc., Fortune Tobacco Corp., Himmel Industries, Inc., Grandspan Development Corp., Asia Brewery Inc.-- all incorporated to Shareholdings Inc.

The court had earlier ruled that the young Marcos' testimony pertaining to the documents would only be admitted in court as evidence if the prosecution presented the original documents or established secondary evidence.

It will be the first time for Imee and Gapud to be called to the witness stand. Their testimony, the PCGG believes, is crucial to the case.

According Bongbong he and Imee were once called to a meeting by their father during which he instructed both of them to conduct an inventory and audit of all of the businesses he owned -- including those under the name of Tan -- when the businessman went abroad.

During that meeting, their father supposedly showed them documents -- deeds of assignment of shares of stock, titles of properties -- and drew a "sketch" of how the structures worked.

On the other hand, Gapud had allegedly signed an affidavit in 1987 where he supposedly stated Tan belonged to the group that could get presidential decrees and letters of instructions from the late dictator for their "joint benefit."