WARSAW, Poland (AP) — A Polish parliamentary commission on Wednesday opened an investigation into one of the country's biggest financial scams that could see Donald Tusk — the former prime minister and current European Union president — called on to testify.

The scam was operated between 2009 and 2012 by a couple and deprived 19,000 people — many of them elderly — of savings worth some 850 million zlotys ($219 million).

The committee plans to question state authorities of the time. Observers say that could include Tusk, who led the government at the time. The parliamentary commission is led by a member of the ruling conservative Law and Justice party, rival to Tusk's party.

Law and Justice, which took power in the fall, blames Tusk and his government for many social ills, such as an inefficient legal system and uneven economic development across the country.

The "Amber Gold" financial scam was a pyramid scheme that exemplifies these ills, the party leaders say. In its electoral campaign the Law and Justice vowed to bring those guilty to account.

The married couple who ran the scheme, identified only as Marcin P. and Katarzyna P., are on trial.

Commission head Malgorzata Wasserman said the aim is to determine why government, banking, justice and security authorities failed to stop the scheme or effectively warn citizens against it.

Marcin P. had a number of suspended sentences for fraud before he started the "Amber Gold" scam and it remains to be explained why he had not been put in prison then.