By 1972, he was making £50,000 with each shipment. By the end of the year he was approached by Hamilton McMillan of the Secret Intelligence Service (MI6), a friend from Oxford University, who recruited Marks to work for MI6 because of his connections in the hashish-producing countries of Lebanon, Pakistan and Afghanistan, for his ability to seduce women, and for his contacts with the IRA. The next year, Marks began exporting cannabis to the United States to The Brotherhood of Eternal Love, hiding the drugs in the music equipment of fictional British pop groups that were supposed to be touring the country; he further expanded his operations with other smugglers and other methods of trafficking, often using his Oxford connections. As McCann was in danger of being executed by the IRA should MI6 tip them off about his involvement in drugs, Marks then gave up the smuggling operation at Shannon airport. Following the Littlejohn affair, MI6 ceased their relationship with Marks, while his American operation came to an end after police opened a speaker full of cannabis and arrested gang member James Gater, leading to other arrests in Europe. Marks was arrested by Dutch police in 1973, but skipped bail in April 1974; the British press then made him a nationally known figure, reporting that he was feared abducted by the IRA for his connections with MI6. With most of his fortune confiscated by the authorities, he made his way to Italy, where he lived in a Winnebago for three months before returning to England in secret in October 1974. At this point he began a relationship with Judy Lane; the couple married in 1980 and had three children together. He had previously been in a five-year relationship with Rosie Lewis, with whom he had a daughter.