Altaf Hussain, the leader of the Muttahida Qaumi Movement (MQM) was arrested on Tuesday in northeast London on charges of money laundering.

Although Scotland Yard would only confirm that a 60-year-old man had been arrested on Tuesday morning in northeast London on charges of money laundering, the website of MQM confirms that the person is Mr. Hussain.

Scotland Yard refused to divulge more details about Mr. Hussain and the specific complaints against him. A spokesperson told The Hindu that he was arrested by officers from the Specialist Operations and is “currently in police custody at the central London police station.” When asked if he had been arrested before, he said “Not in this investigation.”

According to the MQM, Mr. Hussain had been ill for last several days and his doctor had advised that he be shifted to a hospital. The search and arrest warrant was served on him by the police as he was getting ready to go to hospital.

The arrest of Mr. Hussain has sparked protests in his home city of Karachi. A spokesman for the British High Commission was quoted by Dawn as saying that the UK’s consulate in Karachi has been temporarily closed down.

Mr. Hussain grew to political prominence as the leader of the Mojahirs, the Urdu-speaking Muslims, who migrated from India to Pakistan after Partition. The group demands greater rights for the community within the governing framework in Pakistan.

He moved to London in 1991 claiming that his life was under threat from his political opponents in Pakistan.

According to a story that was published in 2013 in the Guardian, Mr. Hussain was one amongst the many people who was given amnesty by former President Pervez Musharraf in 2009. The report said 72 cases against Mr. Hussain were dropped, including 31 charges of murder.

One of his most trenchant critics and political opponents is the cricketer-turned-politician Imran Khan, who accused the MQM of being behind the murder of a Karachi-based party activist Zahra Shahid Hussain in May 2013.

It was then that the London police opened an investigation into Mr. Hussain’s London-based activities. The MQM have denied all charges against him, and have offered to cooperate with the investigating team.

On two occasions British judges have found that the MQM is a violent organisation, the Guardian report said. It quotes from the judgment of Lord Bannatyne, who granted asylum to a Hussain detractor: "The MQM has killed over 200 police officers who stood up to them in Karachi".

Respect Party head, George Galloway, is another implacable critic of Mr. Hussain

After news of the arrest broke on Tuesday, Mr. Galloway tweeted: “Today after a lot of hard work and some courage and determination, the London-based gangster, Altaf Hussain is under arrest. I take my hat off to the metropolitan police and denounce the political class, which remained silent and complicit with the murder mayhem crime extortion organized from London by the Godfather of Edgware and Karachi. Long live Pakistan!”