The man, Salah Abbas Habib, 36, was a leader of antigovernment protests who took part in a demonstration on Friday afternoon. “He then stayed on and went to a protest in the evening, then later in the night he called our cousin and said he had been very tired and was at a farmhouse,” said his brother, Hussain Abbas Habib.
Opposition activists have accused the government of cracking down on demonstrations ahead of the Formula One Grand Prix.
Al Wefaq, the largest opposition group in the kingdom, said Mr. Habib had been among a group of protesters who had been beaten by the police. Abduljalil Khalil of Al Wefaq said, “After listening to witnesses, we say he had been killed by the police.”
An uncle of Mr. Habib said friends had told the family that Mr. Habib had been found on a rooftop and that his body showed signs of beatings.
Bahrain has suffered unrest since last year when opponents of the government tried to follow other Arab Spring revolutions with their own. But the government cracked down brutally, and Saudi Arabia sent in troops to ensure the protests were squelched.
The West, including the United States which bases its Fifth Fleet in Bahrain, has been relatively muted in its criticisms of Bahrain’s leaders. Activists had hoped to use the car race to again raise their complaints with their government and its supporters outside the country.
On Saturday, Bahrain’s chief of public security, Maj. Gen. Tariq Al Hassan, said that the police had received a call around 8 a.m. alerting them to the discovery of a body in Shakoura, a village outside Manama, the capital.
He confirmed that the deceased was Salah Abbas Habib and said “the death was determined to have happened under suspicious circumstances.”
The Minister of the Interior said an investigation was under way and asked for calm.
Mariam Isa Ali Jawad, 33, Mr. Habib’s wife, said that her husband was attending daily demonstrations and was one of the protest leaders in the Shakoura area.
She said he was a member of a group that the government has accused of encouraging protesters to throw homemade bombs at the police. But Mrs. Jawad said her husband had opposed the use of violence.
Mr. Habib, who had been working as a gardener for the government, had been arrested in 1990s for membership in groups that called for the downfall of the ruling Khalifa family. She said he was jailed for five years for his political activities.
About 30,000 people attended a protest Saturday calling for a boycott of the Formula One race. Mr. Khalil if Al Wefaq said the presence of members of the international media would give protesters an opportunity “for raising our voices.”