Spanish police nab South Florida supermarket mogul wanted in 2011 alleged slaying of wife's lover Police say Marin is the alleged mastermind behind the killing of a man in 2011.

A former co-owner of a grocery chain in South Florida who police say is the alleged mastermind behind the slaying of his wife's secret lover has been arrested in Spain this week after seven years on the run, authorities said.

The Miami-Dade Police Department, which is investigating the case, received a call from Spanish authorities on Tuesday that they had detained Manuel Marin, 64, after making contact with him and realizing that he was wanted in the United States for second-degree murder, among other charges. Marin is awaiting extradition to the United States, Miami-Dade Police Detective Alvaro Zabaleta told ABC News.

The Miami Dade State Attorney's Office confirmed in a statement to ABC News on Friday that Marin "is in custody" and that "extradition is proceeding."

Spanish newspaper El Pais reported that Marin was arrested at the U.S. Embassy in Madrid after police officers there observed him acting nervously. Spanish police did not immediately respond to ABC News' request for comment.

The U.S. Department of State said it does not comment on pending extradition requests.

Marin is one of four suspects in the grisly murder of 43-year-old Camilo Salazar, who was having an affair with Marin's wife, police said. Salazar was found dead on a dirt road in northwest Miami-Dade in June 2011, a day after he went missing, according to police. He had been beaten, his hands were bound, his throat was slit and his groin was burned, police said.

Investigators determined that Marin, a part-owner of Presidente Supermarkets at the time, found out about their relationship and confronted the two. Then, he allegedly enlisted the help of two mixed-martial arts fighters and a boxing promoter to kidnap and murder Salazar, according to police.

Just days after the killing, Marin packed his bags, took his passport and fled the country for Spain, according to police. He left his business behind in the hands of his son, who still runs several Presidente Supermarkets in South Florida, police said. On its website, the Hispanic grocery chain claims it is one of the fastest-growing in the United States.

The company did not immediately respond to ABC News' request for comment Friday.

Marin’s wife has not spoken publicly about the affair.

Over the years, police were able to locate the other three suspects: former mixed martial artists Alexis Vila Perdomo and Ariel Gandulla, as well as fight trainer and promoter Roberto Isaac. Vila Perdomo and Isaac were arrested in April and have pleaded not guilty, while Gandulla remains at large and is living openly in Vancouver, according to police.

Perdomo, 47, and Isaac, 62, have trial dates scheduled for Oct. 22. They are being held without bond in the meantime, according to court records.

Miami-Dade police have filed an arrest warrant for Gandulla, 50, and are working with Canadian authorities, Zabaleta said.

"We know exactly where he is," Zabaleta said of the ex-MMA fighter. "We also knew that Marin was in Spain."

All four suspects face charges of second-degree murder, conspiracy to commit second-degree murder and kidnapping in connection with Salazar's death.