Watch: Inside Tunisia Gunman's Apartment

Seifeddine Rezgui’s apartment was bare and filthy, according to newly emerged footage that appears to show the inside of the Tunisia gunman's flat.

It was not clear when the footage by Tunisia's Mosaique was taken. The station's YouTube page said the video was published on Saturday.

Empty bottles, pots and plastic bags lie underneath the basin while the floor is covered in dirt.

A knife and fork still lie on a dinner table while the fridge is empty and dirty except for a few potatoes, chili peppers and what seem to be tomatoes.

Rezgui was a 24-year-old aviation student who was previously unknown to Tunisia's counter-terrorism officials and appears to have been radicalised in the last six months.

Just how that happened will be the focus of the Tunisian investigation into the shooting, which left 38 people dead, including reportedly 30 Britons , on a beach resort last Friday.

Islamic State has claimed responsibility for the attack - and in Twitter messages, referred to Rezgui using the jihadist pseudonym Abu Yahya al Qayruhni.

Another video that emerged in the aftermath of the massacre shows Rezgui breakdancing.

The video, taken five years ago, was posted on a Facebook page set up by a group of friends interested in rap music. It shows Rezgui wearing skinny jeans, a hoodie and a baseball cap as he performs spins and handstands to a techno soundtrack.

Rezgui was born in Gaafour - a town approximately 100 miles from Sousse, the site of the massacre.

He had never travelled abroad in his lifetime, prompting fears that he was radicalised at home, potentially at a local mosque.

Friends told Sky News that even two days before the attack, Rezgui showed no signs of radicalisation, visiting a cafe and going for a walk.

Those accounts were backed up by the killer's uncle Ali al Rezgui, who told the Telegraph the family had seen nothing to worry them - although Seifeddine Rezgui had apparently been traumatised by the death of his brother in a lightning strike in 2010.

Mr Rezgui told the paper: "He used to use hair gel and wear the nicest of clothes, and he used to do break dancing.

"He even used to go to competitions and things like that in Tunis, he was well known for that here. He didn't even have a beard, and I've never seen him with anyone with a beard.

"We have extremists like that in Gaafour, but never have I seen him with them. Now he's shooting people with a Kalashnikov, it's just so confusing."