Police have published the names and faces of 12 of the most wanted British criminal suspects thought to be hiding in Spain, in an effort to track them down. A joint campaign involving Spanish and UK police forces was launched on Wednesday in Madrid with a picture gallery of men wanted in connection with crimes including murder, drug trafficking and arms smuggling. The list of alleged fugitives thought to be hiding in mainland Spain or the Spanish islands includes two men accused of killing members of rival criminal gangs. According to the National Crime Agency list, Nana Oppong, 41, is wanted by Essex police in connection with the drive-by killing of Robert Powell, 50, who was shot eight times with a pistol in June 2020. Callum Halpin, 27, is wanted by Greater Manchester police over the 2018 killing of Luke Graham, 31, in a gang turf war. The list also includes Jack Mayle, 30, from Croydon, who allegedly sold the class A drug MDMA via a phoneline in south London called the Flavour Quest. When he fled the UK, according to the NCA, his tattoos included a diamond under his left eye and the word Croydon on his left forearm. The National Crime Agency’s director general of operations, Steve Rodhouse, who attended the launch alongside the Spanish security minister, Rafael Pérez Ruiz, insisted that Spain was not a “safe haven” for criminals. He said: “The last thing the fugitives’ associates will want is the combined determination and capabilities of the UK and Spanish law enforcement focusing on them.” Rodhouse said many of the wanted men on the list would have tried to blend in with British communities in Spain. In an appeal to expats for information, he said: “Loyalties change over time and we urge anyone with information about these men to help us find them.” The list also includes two suspected drug dealers from Cardiff who used the secret phone network EncroChat before it was taken down in an international operation. Asim Naveed, 29, described as muscular and 6ft 2in, is accused of being the leader of a drug smuggling gang that brought 46kg of cocaine, worth nearly £8m, into Wales between February and June 2020. His alleged customer Calvin Parris, 32, who has gold upper teeth, is accused of selling cocaine in the Welsh capital. Another suspect is James “Jamie” Stevenson, 56, who is wanted by the National Crime Agency and Police Scotland after the seizure of about 1 tonne of cocaine at the Port of Dover in September 2020, and 28m “street Valium” tablets in a raid on a suspected pill factory in Kent in June that year. Stevenson, who is stocky and described as having a scar on the left side of his face, is also wanted in connection with two suspected arson attacks in Lanarkshire and Forth Valley in May 2020. Pérez Ruiz said: “The campaign allows us to reinforce and strengthen police collaboration between Spain and the United Kingdom with the aim of creating a hostile environment which impedes criminal organisations from setting up in Spain and criminals from settling in our cities.” Anyone with information can call Crimestoppers anonymously in the UK on 0800 555 111 or from Spain on 900 926 111, or online at crimestoppers-uk.org/fugitives.