BUENOS AIRES — The driver took copious notes.

In cheap spiral notebooks commonly used by schoolchildren, the driver, Oscar Centeno, meticulously recorded a decade’s worth of trips hauling bags of cash to be delivered to government officials from businessmen who had been awarded large government contracts.

Now eight of Mr. Centeno’s notebooks are at the heart of a large-scale corruption investigation unveiled this week as the authorities carried out dozens of raids, arrested 16 people and continued to seek two others, rattling the political and business elite of a nation where corruption has seldom led to meaningful punishment.

Some Argentines have compared the case to the so-called Car Wash investigation in neighboring Brazil, which revealed how graft had infused the country’s political system and led to the conviction of more than 100 people, including former President Luiz Inácio Lula da Silva of Brazil.

Most of those implicated in Argentina’s notebook case so far are close allies of former President Néstor Kirchner and his wife and successor, Cristina Fernández de Kirchner, whom prosecutors described as the leaders of a wide-ranging conspiracy.