Spain's Foreign Ministry summoned the Cuban ambassador Monday to explain why a Spanish politician who has promoted ties with Cuban opposition figures was denied entry to the island and held for a couple of hours before being sent back home.

It was unjustifiable that Luis Yanez, a Socialist who now holds a seat representing Spain at the European Parliament and has served under a previous Spanish government, was not allowed to enter Cuba, the ministry said in a statement.

The ministry's top official for Latin America, Juan Pablo de Laiglesia, called ambassador Alejandro Gonzalez Galiano to come in on Tuesday to provide an explanation.

Yanez was detained upon arrival and expelled from the communist-run Caribbean country before dawn Monday, the ministry said. There was no immediate comment from Cuban officials in Havana, and no one answered the phone at the Cuban embassy in Madrid.

Neither the foreign ministry statement nor a ministry official said why Yanez was visiting.

Yanez has promoted contacts between European socialists and democratic Cuban dissidents as president of a group called Cuba-Europe in Progress.

Posted on the group's Web site is a column Yanez wrote in the Spanish newspaper El Pais in 2007 decrying "the disappearance of the most minimal freedom of expression and of artistic creation" in Cuba, as well as the jailing of dissidents.

The Cuban co-president of the group is listed as Manuel Cuesta Morua, head of the Progressive Arc group. He told The Associated Press that Yanez had indicated that he planned to visit with him during his trip.

"I think that (the authorities) are taking reprisals," Cuesta said.

An official with the Spanish Socialist Party said Yanez and his wife Carmen Hermosin, who is member of the Spanish parliament, had traveled to Cuba on a tourist visa for a private trip with no political meetings planned. She flew back with her husband.

The official spoke on condition of anonymity in line with party rules.

In recent years, Cuba has refused entry to several European and Spanish parliamentarians who arrived on the island with tourist visas but who were believed to be planning to meet with dissidents.