Hundreds of migrants were found aboard a luxury yacht after paying up to $2,500 each for the voyage to Europe.

The 100-foot vessel ? which had a regular capacity of about 65 people ? was carrying 345 Syrian nationals when it was intercepted just off Tsonia beach on the Greek island of Lesbos on Monday, officials said.

A coast guard source said the 15-year-old boat would cost more than $1 million if bought new, adding it was the first recorded instance of such an expensive vessel being used to traffic migrants and refugees to Greece.

The yacht did not carry a name or a flag and its ownership was not immediately clear, according to a coast guard spokesman.

Sources familiar with the investigation said that the refugees on board paid up to $2,500 to make the crossing from Turkey. At that price, the journey could have earned traffickers as much as $862,000.