A mysterious masked figure has been popping up across London carrying out random acts of kindness, from paying for people's fuel to filling potholes and even selling Freddos for their long-lost price of 5p.

Known only as "London's Batman", the caped crusader has built up a large online following by turning up across the capital and offering help to strangers.

After weeks of speculation, BBC London was invited to meet London's Batman, who insisted: "It's not about who I am underneath. It's what I do that defines me."

The invitation contained only a time and location, leaving plenty of uncertainty about what, or who, would appear.

In a deserted alleyway, the dark figure eventually emerged.

Asked why London needed a Batman, he said: "I believe that anyone can be a hero. I want to show the good in London. People are struggling and I want to help them."

The mystery surrounding his identity has become almost as popular as the good deeds themselves.

Omilana, however, denied it.

"BBC, just to tell you, I'm not Batman," he said in a voice message to BBC London - although that has done little to end the speculation.

Roy Patrick, a content creator, said he believed it could still be Niko despite his denial.

He said: "When he used to run for prime minister, he went round filling up potholes, trying to make a change."

Patrick said of London's Batman: "It could be him, it may not be him. He might have got someone else to go and dress up for him.

"These are all just conspiracies but, for me and for a lot of people, it's giving Niko Omilana," he said.

Others suggested links to satirical political figure Count Binface, and pointed to the cut-price Freddos, which featured in one of his manifesto pledges.

London's Batman would not reveal to BBC London who he was, where the money for his giveaways came from, or whether the project was partly designed to create online content.

The Instagram account has attracted more than 97,000 followers in less than a month, and his videos have repeatedly racked up hundreds of thousands of views.

Social media expert Rhea Freeman said: "I think these videos are successful for a few reasons. One, there is a fully-grown human dressed as Batman in the middle of London. But also it is positive.

"It's very much tapping into the current times. Fuel is incredibly expensive. There is a cost of living crisis. I think it is shining a spotlight on things a lot of us are feeling."

She added that viral content could financially benefit creators through advertising revenue, sponsorships and brand deals.

Creators can earn money directly from video views, and large online audiences can attract further commercial opportunities.

London's Batman insisted his mission was simple.

"It's to help London and give them hope for a better tomorrow," he said.

"I just want to help make the place better. Unite the people."

For many of those who have received a freebie, a helping hand or simply a reason to smile, London's Batman is perhaps less about the identity and more about the idea.