We bought a flat and made an incredible discovery… there was no trace of it on any of the paperwork

A couple were stunned to discover a mysterious room while renovating their new home.

British TikToker Erin Cloudy was renovating her home when she made a shocking discovery: a hidden door under the stairs that led to an entire secret room “as big as her flat,” and a network of underground tunnels.

She shared a video on TikTok and took viewers along as she explored her bizarre new property.

Posts under her handle @erincloudyshe talked about the moment they came across the hidden door.

They had just started knocking down a wall under the stairs – they didn’t expect to encounter another staircase leading to an old door.

Erin filmed the incredible discovery and said: ‘Under the stairs we broke it through, and you look through this hole and it’s just a staircase. What the f***? and a door?

Someone who helped her with the renovation commented: ‘It goes even further down’ with another staircase behind the door, leading down into the darkness.

Unable to hide their shock, they walked through the door and exclaimed, ‘It’s as big as your flat down here. Oh my God’.

The video stopped just before they reached the secret room, but Erin quickly filmed a second part to keep viewers updated.

She wrote in the caption: ‘So my flat is a ‘basement flat’, nothing is mentioned under me, verbally or on the title deed. We were curious about the storage space under the stairs and decided to take a look.’

They followed the hidden tunnel and found themselves in a huge underground chamber, complete with an ancient fireplace and functioning light.

Erin’s flat is on the bottom floor, with three other flats above her and nothing listed below.

The surprise didn’t end there, however, as she discovered a network of underground tunnels leading from the secret basement room, some of which had access to the streets above.

Equipped with her phone camera and a flashlight, she began exploring the whole new level she never knew she would reach.

The TikToker wrote: ‘I can’t handle this building! I didn’t used to panic, but now I do! As you can see there are a few rooms I would have to crawl into and I’m not sure I want to!

‘I want to know what their purpose was and why they don’t have big doors?! Any idea?’

She made her way through the filthy crawl space and said, “It looks like Barbarian, oh, it stinks.

“Oh my days, it goes on and on. Oh, I don’t know, I can’t go in there. It keeps going. I truly bless this house.”

She turned the camera towards what appears to be an endless passageway leading to smaller spaces.

Now scared of what started out as a fun discovery, she added, “It’s going down the road. This is all beneath me. I’m not going to be able to sleep.”

Social media users couldn’t believe what they saw and urged the new homeowner to show them more.

In one clip, Erin showed viewers what her entire building looks like from the outside, explaining that she had no idea about the basement.

She said, ‘Okay, this is the whole building and there are three flats above me, and this is my floor and my door.

‘Then there’s a little courtyard and this, which I noticed when I bought the flat, but I thought it was a little coal house.

‘Then when I look closer, I see a window, which I think is the window in the secret room. We’re going to clean this up and go inside.

“And when I viewed the house before I bought it, there were a lot of plant pots on this little window, so I didn’t actually see that part.”

Besides the tunnels, the property has some interesting quirks that left Erin with a plethora of questions.

In the tunnels and in the small courtyard at the front of the building she found a number of barred windows and doors with nothing but bricks behind them.

She wondered, “There’s another barred window. Where is that going? It’s a wall, I think, someone has bricked in a window.

‘That’s the basement. For some reason there are bars that are bent down.”

On her level of the building, she found a square hole in the wall, which she thinks could be a proofing oven.

She guessed, “Maybe this was the kitchen area and the ground floor was the servants’ quarters.”

The video series, which was originally posted in January, has captured the attention of millions of users, who flocked to the comments to give their verdict on the unique flat.

One user wondered: ‘Has no one seen Barbarian?’, while a second user added: ‘Absolutely not. I’ve seen Barbarian. I would seal it up and move it.”

In the 2022 horror film that viewers keep comparing the apartment to, a young woman discovers that the rental house she booked is already occupied by a stranger and has some very dark secrets in its underground tunnels.

A third wrote: ‘People don’t understand how much of a bonus this is, a little renovation and you’ve practically doubled your floor space.’

“That’s a very nice room, but why was it locked?” asked another commenter.

Meanwhile, someone else secretly advised, “Don’t say anything, just go in.” Storage’.

“You should look up the history of the place and see if you can find the reason why they boarded it up,” another suggested.

However, most viewers were terrified by the discovery and joked to keep them informed of any ‘paranormal activity’ and that the bars had been broken because of a ‘demon’.

Someone joked, “If something gets sealed with cement and wood and you keep going and it gets sealed again, then maybe it should stay sealed.”

Another wrote: ‘With every video I expect you to turn the corner and there’s a skeleton lying there.’

Erin hasn’t updated her followers about the house since late January, with many begging for more videos.

MailOnline has contacted the TikToker for comment.