HAVANA, Cuba (CNN) -- European diplomats visited the family of a jailed Cuban dissident Thursday over concern the government has arrested him on criminal charges in a bid to block his political activities.
Cuban leader Raul Castro, seen August 10, says he would be willing to talk with the U.S. about political prisoners.
Representatives from Sweden, the current president of the European Union, as well as diplomats from the United Kingdom, Germany, Hungary, and Poland, drove to the Havana home of Darsi Ferrer and talked to his wife.
Ferrer has been an outspoken critic of the Cuban government and has even organized small marches to demand improved human rights in Cuba, an unusually bold move.
Ferrer was arrested last month. But according to his wife, the charges are not political.
She says he is being accused of verbal aggression and stealing cement.
"They were two sacks of cement to fix this humble house," she told the visiting diplomats and journalists. "We didn't grab a cement truck, they were two sacks of cement that were donated by neighbors."
The government won't disclose any details about the case.
But some European governments are worried the charges could be a new tactic against opponents.
Ferrer "is somebody that somehow is representative of a new type of dissidence," said Swedish diplomat Ingemar Cedeberg.
"I think the authorities are not just using the normal instrument these days, short arrests. They're trying to invent something new. And that is very preoccupying."
In 2003, Cuba cracked down on dissidents, jailing 75 of them for conspiring with an enemy government.
Their wives, sisters and mothers formed the Ladies in White, marching every week to demand their loved ones' release. Some have been freed.
Some government critics hope the situation for dissidents could improve if and when U.S.-Cuba relations get better.
Cuban President Raul Castro says he would be willing to talk about everything with Havana's old foe -- including political prisoners.
But human rights groups say the number of dissidents in jail is now at the highest level in three years.
European diplomats say, for now, they just want the reasons for Ferrer's arrest clarified.
"Let's hope that it is not a new tendency, that it is just a single case," said Cedeberg.