David Cameron has urged the Crown Prince of Bahrain to embrace "reform rather than repression" in response to pro-democracy protests in the Gulf state, according to Downing Street.
Sheikh Salman bin Hamad al-Khalifa's visit to Number 10 has been criticised by human rights campaigners after his regime's bloody crackdown against Bahraini demonstrators.
Downing Street said Mr Cameron, who shook hands with the Crown Prince on the steps of Number 10, "raised concerns" inside about the situation in Bahrain.
Bahrain has been widely condemned for inviting neighbouring Saudi Arabia to send in troops to help put down protests against the ruling al-Khalifa dynasty.
The Sheikh's visit to London comes after he declined an invitation to the wedding of the Duke and Duchess of Cambridge last month amid fears that protests against his presence might tarnish the event.
Bahrain is due on June 1 to lift the martial law imposed in March following weeks of pro-democracy protests which resulted in the deaths of at least 29 people. Hundreds of people have been arrested and dozens put on trial in special courts.
A Downing Street spokesman said Mr Cameron and the Crown Prince discussed both Bahrain and the wider Middle East, adding: "The Prime Minister raised concerns about the situation in Bahrain and stressed the importance of the Government moving to a policy of reform rather than repression. That all sides should address their grievances through genuine and constructive dialogue.
"The Prime Minister emphasised his support for the Crown Prince's long-standing work to achieve political and economic progress in Bahrain, and said that Britain would back efforts to normalise the situation and return Bahrain to a credible long-term process of reform."
Challenged earlier why Britain was welcoming the Crown Prince when it was engaged in military action in Libya, the Prime Minister's official spokesman said "the situation in different countries is different".
"There are different circumstances and we need to reflect that. Clearly, in all cases we would support reform and dialogue," he said.