A UK-based journalist for independent Iranian media who was attacked outside his London home, prompting a counter-terrorism police probe, is "doing very well", his news channel said on Saturday.

Pouria Zeraati, a presenter for Persian-language outlet Iran International was in stable condition, the channel's spokesman Adam Baillie said.

"He's doing very well actually. He's in the hospital recovering from the attack," Baillie told BBC radio, calling Friday's attack "a shocking, shocking incident whatever the outcome of (the) investigation reveals".

London's Metropolitan Police has said its counter-terrorism unit is investigating the stabbing, given previous hostile threats by Iran against perceived opponents in Britain.

The force said the motive was unclear and officers were keeping "an open mind", but that "the victim's occupation as a journalist at a Persian-language media organisation based in the UK" was being considered.

Zeraati, in his 30s, sustained injuries to his leg in the mid-afternoon attack outside his home in Wimbledon, southwest London.

Announcing the incident on social media, Iran International noted it came after Tehran was implicated in a plot to kill two of its television anchors in 2022.

Baillie said the channel's journalists and their families and others had been repeatedly targeted and threatened by the Iranian Revolutionary Guards Corps (IRGC).

"Along with our colleagues at BBC Persian, Iran International has been under threat, very heavy threats, for the last 18 months since the IRGC said 'We're coming for you'," he added.

Baillie said the paramilitary security force gets "in touch through proxies" and its tactics include taking in relatives for questioning and threatening in Iran.

"The scale of that has increased dramatically over the last few months. And the scale and the type of questioning is more aggressive," he added.

The Met has disrupted what it has called plots in the UK to kidnap or even kill British or Britain-based individuals perceived as enemies of Tehran.

An Austrian national was convicted last December of spying for a group that may have been preparing to attack Iran International.

The Iranian government has declared the outlet a terrorist organisation after it reported on protests sparked by the death of 22-year-old Mahsa Amini.

She died in 2022 after her arrest in Tehran for an alleged breach of the Islamic republic's strict dress code for women.

The UK government last year unveiled a tougher sanctions regime against Iran over alleged human rights violations and hostile actions against its opponents on UK soil.