Violence erupted in Karachi after MQM’s Altaf Hussain, who has been living in Edgware for over 20 years, addressed supporters in the city via a telephone call.
The police are examining Hussain’s speech following “numerous calls from the public” to see if his remarks broke any English laws, a Scotland Yard spokeswoman told the Guardian.
She added, “Where evidence of criminal activity is found we will consult with the Crown Prosecution Service.”
Authorities in Pakistan claimed Hussain described the country as a “cancer” and incited his followers to attack two media stations that he accused of bias.
On the other hand, an MQM spokesman claimed that the violence flared after the party’s supporters were fired on by police where one person was killed.
MQM’s Altaf Hussain has already been under investigation since last summer following previous speeches.
The Metropolitan police have been probing many old speeches made by Hussain, who holds joint British-Pakistani citizenship, one of the three separate cases by the force into Hussain and other MQM members.
MQM’s deputy leader Dr Imran Farooq was stabbed to death outside his north London home in September 2010, activating a murder probe.
“Detectives from the Met Police Counter Terrorism Command (SO15) are investigating Dr Farooq’s murder and remain committed to putting before the courts those responsible,” a Met spokeswoman told the British media group.
Police raided properties linked to the MQM and found huge amounts of cash, leading to a new money-laundering investigation by fraud specialists.
As part of the money-laundering case, Hussain was held in June 2014 but later released on bail. Five other MQM leaders were also arrested and bailed, although bail was cancelled on all six men in February 2016.
Wasay Jalil, a member of MQM’s coordination committee based in London, said the party was not using London as a base to incite violence.
“We’ve never used British soil for terrorism,” Jalil told the British media group on Tuesday. “We always act within peaceful political structures.”
Hussain apologised for his remarks on Tuesday, blaming “mental stress”. MQM’s Jalil constantly sought to play down rumours of a split within the party, a senior party member Dr Farooq Sattar distanced MQM from Hussain’s comments, saying the party should now be run “from Pakistan alone”.