HONG KONG—Macau police said on Sunday they had arrested 11 people in an investigation into an illegal gambling and money-laundering syndicate, a day after businessman Alvin Chau, who organizes trips to Asian casinos for big spending gamblers, was questioned at a police station. The police said in a statement that people involved in the case acknowledged the group had operated gambling websites or telemarketing activities in other places. Hong Kong’s South China Morning Post reported that at a news conference on Sunday, Macau’s judiciary police did not name the individuals but said they included a 47-year-old Macau businessman surnamed Chau. It was not clear if this was Alvin Chau, who is chairman of Suncity Group Holdings Ltd. He is also the founder of a separate legal entity also called Suncity, the region’s biggest “junket operator,” which runs VIP gambling rooms across Asia. Junket operators are go-betweens who bring high rollers …