MADRID — Spain’s governing Popular Party was drawn deeper into a web of corruption scandals this past week, after the Swiss authorities informed the Spanish judiciary that the party’s former treasurer had amassed as much as 22 million euros, or $29 million, in Swiss bank accounts.

The treasurer, Luis Bárcenas, resigned from his job in 2009, after being indicted in the early stages of an investigation, which is still ongoing, into a scheme of kickbacks and illegal payments allegedly involving other conservative party politicians.

Mr. Bárcenas has said that he is innocent and that the Swiss accounts were held on behalf of investors. The Popular Party, too, denied any link to the money. Alfonso Alonso, the party’s parliamentary spokesman, said at a news conference this past week that he and other party members were “outraged” by the discovery and called on the prosecuting judge to pursue the case “to the end.”

Nonetheless, the revelations have brought a fast-growing list of corruption investigations, which have unspooled across Spain, to the doorstep of the conservative government of Prime Minister Mariano Rajoy, who has so far remained silent. About 300 Spanish politicians from across the party spectrum have been indicted or charged in corruption investigations since the start of the financial crisis. Few have been sentenced so far.