The trial of a Polish couple charged with cheating some 19,000 people out of savings worth some 850 million zlotys ($225 million) has begun, in what is one of the country's biggest financial scandals since the end of communism in 1989.

The trial before the Provincial Court in the northern city of Gdansk commenced Monday after a two-hour delay, because the building was security-checked following a bomb threat call.

Prosecutors have charged the couple, identified only as Marcin P. and his wife Katarzyna P., with fraud and money laundering from 2009 -2012, when they ran the "Amber Gold" quasi-bank that proved to be a pyramid scheme.

Most of their clients were elderly people, many of whom lost their life's savings.

If convicted, the pair could face stiff prison terms.