The exiled leader of Pakistan's MQM party has been bailed by police in London after being arrested on suspicion of money laundering, a police source has said.
Altaf Hussain was arrested at his home in the British capital on Tuesday, prompting thousands of people to protest on the streets of Karachi, Pakistan's biggest city and his party's power base.
"The 60-year-old man arrested on Tuesday 3 June on suspicion of money laundering has been released on police bail to a date in July pending further enquiries," a police statement said,
A police source indicated to the AFP news agency on Saturday that the man was Hussain.
Police added that investigations in the case were continuing. Hussain left Pakistan for the UK in 1992 after a military operation to end ethnic unrest in Karachi and he gained British citizenship in 2002.
He remains a highly influential figure in Karachi, Pakistan's economic centre and main port, wielding effective control over the city from his London home and addressing supporters using a loudspeaker linked to his telephone.
As well as major protests, which included the torching of at least a dozen vehicles, his arrest prompted the Karachi Stock Exchange to plunge three percent while train services were also halted.
Following the arrest, the office of Pakistani Prime Minister Nawaz Sharif issued a brief statement expressing solidarity with Hussain.
"The Prime Minister has also directed the Pakistan High Commission in London to provide counsellor services to Mr Altaf Hussain," the statement said.
"The government is ready to provide all kinds of legal and moral support to Mr Altaf Hussain."
Raids on home
Hussain founded the MQM in 1984 in response to the marginalisation of Mohajirs - migrants who fled India amid the violence of the sub-continent's partition.
They are mainly concentrated in the cities of the southern Sindh province, especially Karachi where they form a majority of the city's population of 20 million.
Hussain is revered by his fiercely loyal supporters while his critics accuse him of running his party as a violent, mafia-like organisation.
Following his arrest, he was allowed to attend a pre-arranged medical appointment on Tuesday and was kept in hospital until Thursday.
Police previously raided his London residence in 2012 and 2013, also over money-laundering claims.
Two other men were arrested over the allegations in December last year and have been bailed until September pending further investigations.