Perhaps she really is a time-traveller, sent back through the decades to make a jaw-dropping cameo appearance.

Or maybe she was a maverick genius, secretly testing out advanced technology for the government and caught on camera at the wrong moment.

Whatever the explanation, this footage from a Charlie Chaplin promotional film in 1928 showing a woman apparently using a mobile phone has left viewers stumped.

A traveller from the future? This clip from a film about the premiere of Charlie Chaplin’s 1928 movie The Circus shows what appears to be a woman talking on a mobile phone in the opening scene (on the right)

The baffling scene is found in the extras section of The Circus and shows members of the public attending the premiere of the film at Manns Chinese Theatre in Hollywood.

The short piece of footage shows an older woman dressed in a coat and hat with her hand held up to the left-hand side of her face as she talks.

There is no one around for her to be speaking to apart from a suited man who strides on ahead at the beginning of the shot.

Even her gestures and behaviour as she ‘talks’ will be eerily familiar to modern-day viewers as she appears to stop, mid-sentence, during her apparent conversation.

The bizarre anachronism was unearthed by film buff George Clark on his Charlie Chaplin box set.

Woman out of time: A close-up of the image shows the woman’s hand is close to her face and she appears to be talking

He says he has shown it to more than 100 people and still no one can come up with a convincing explanation.

Some viewers have suggested she is listening to a portable radio close to her face, although this would not explain why she appears to be talking.

Others say she may be displaying signs of schizophrenia and covering her face to hide the fact that she is talking aloud to herself.

It has also been suggested that she is simply trying to hide her face from the camera so she is not filmed.

There are also sceptics who believe the footage is just a stunt created by Mr Clark – a film maker with Yellow Fever Productions – to publicise his latest film festival.

The first device that could be likened to a mobile phone was Motorola’s original ‘Walkie-Talkie’ which was developed in the 1940s, but that was the size of a man’s arm and still came more than a decade after the Chaplin film.

See you later… As the scene fades out, the mystery figure can be seen smiling

The main attraction: In The Circus, Chaplin’s character falls in love with the circus-owner’s daughter

Portable mobile phones that we would recognise today did not appear until the 1980s and even then they were still too big to hide in the palm of your hand.

In a video that Mr Clark has posted on YouTube he jokes that the only plausible theory is that the woman is a time traveller.

He says: ‘This short film is about a piece of footage I found behind the scenes in Charlie Chaplins film The Circus.’

‘Attending the premiere at Manns Chinese Theatre in Hollywood, California – the scene shows a large woman dressed in black with a hat hiding most of her face, with what can only be described as a mobile phone device – talking as she walks alone.

‘I have studied this film for over a year now – showing it to over 100 people and at a film festival, yet no one can give any explanation as to what she is doing.

‘My only theory – as well as many others – is simple… a time traveller on a mobile phone. See for yourself and feel free to leave a comment on your own explanation or thoughts about it.’

Chaplin’s The Circus was one of the master director’s final silent movies and won him the Academy Award in 1929 for ‘Versatility and genius in writing, acting, directing and producing’.

It tells the story of the Tramp, who works as a clown in a circus and who falls in love with a circus-master’s daughter.

Chaplin produced the film at the height of the legal fallout over his divorce from Lita Grey and he did not mention it once in his autobiography, even though it is now regarded as one of his masterpieces.