Tulisa this week delighted fans by making her long-awaited TV return on I'm A Celebrity... Get Me Out Of Here! 

But since entering the jungle, the N-Dubz star, 36, has been mocked relentlessly for her changing appearance. 

Close friend Rylan even took to X in defence of the singer arguing she had 'been through a lot' in the last few years — including recovery from facial paralysis which, she says has altered her natural look — and shouldn't be the butt of cruel jokes.

Yet viewers have now fixated their attention on her hairline, arguing her locks 'aren't real' or 'natural'. 

Others accused her of 'wearing a wig' given 'her hair just looks too perfect' for the jungle.  

In one TikTok seen 735,000 times, @lidiahughesrodriguez said: 'Anyone else see a wig line?'

Another, watched more than 213,000 times, said: 'Her hairline looks really full. It doesn't look natural.

'I like Tulisa, it's not a dig at all. Her hair looks thick and full and lovely, I am totally jealous.

'The hairline is really round, maybe she's had a hair transplant. 

'But when she frowns, it looks like it's glued down. I think she's wearing a wig.' 

Now experts have weighed in, suggesting her hairline bears the hallmarks of a 'possible surgical intervention'. 

Images of the star at the height of X-Factor in the early 2010s show a change in her hair density and thickness, as well as slight shift in hairline position.  

Dr Glyn Estebanez, an aesthetic surgeon and founder of Dr Glyn Medispa in London, told MailOnline: 'While it's difficult to pinpoint without confirmation, some tightening or lifting procedures can subtly alter the position of the hairline due to skin repositioning.

'We can see gentle [hairline] lifting with treatments like Thermage FLX as a non-surgical alternative to a brow lift. 

'This is an alternative for patients who don't want to go under the knife.'

It involves tightens and firms skin using radiofrequency technology. 

'Injectable treatments like anti-wrinkle injections if administered incorrectly can create a puckering effect near to the hairline too,' he added. 

Dr Shehab Jabir, a consultant plastic surgeon at Centre For Surgery in London, also said while only Tulisa could confirm any work, 'changes in hairline position' may indicate a hairline lowering procedure has taken place. 

Hairline lowering involves moving the scalp forward using intricate cuts and suturing to reduce the height of the forehead. 

It's often done to create a more balanced facial proportion for people who feel their forehead is too prominent.

Another surgical intervention includes hair transplants, which involve relocating hair follicles from one part of the scalp, typically the back or sides, to areas that are thinner or balder.

Dr Jabir: 'An increase in hair density, particularly in areas that were previously thinning, might suggest a hair transplant. 

'The new hair growth can create a fuller appearance, and while modern techniques aim for natural results, subtle differences in hair texture or direction may be observed after looking more closely.

'In the case of hairline lowering, faint zig zag scars near the hairline or around the temples might be seen. 

'For hair transplants, tiny dots or slight irregularities in hair patterns can sometimes be seen where follicles were implanted as part of the procedure.'

The much-loved star has been no stranger to queries about her appearance over the years, candidly discussing the work she has had done. 

Earlier this year she told Olivia Attwood's So Wrong, It's Right podcast she would get filler to counteract the swelling caused by Bell's palsy, a type of facial paralysis. 

It can cause the muscles to lose control, provoking twitching, weakness or even losing the ability to move one or both sides of the face. 

'Because I had this low-level swelling, I then dissolved all the filler and I would match the inflammation by putting filler in the other side,' she told the podcast. 

'So you have this side swollen and this side is filler to match to the swelling.'

But this isn't the first health issue the singer has had to contend with, after developing another severe and painful disorder as a teenager.

In her tell-all book, Honest: My Story So Far, released in 2012, she also admitted she suffered from dermatillomania — a condition that causes people to compulsively pick at their skin.

She wrote: 'Picking at my face was my way of zoning out, I guess, and sometimes I would go into the bathroom and just pick at my skin for hours, not realising that I'd developed an anxiety disorder of my own.

'As far as I was concerned, it was just something I did to get away from my mum.

'But it got so bad that eventually I was tearing into my face with nail clippers and tweezers, just to get at any minute blemish or invisible little bump under my skin.

'At times I caused absolute catastrophe on my face, leaving gaping, weeping holes that must have looked horrendous. 

'I was extremely lucky that my skin always healed quickly and without too much scarring.

'I did this almost every day for years, and it's only three years ago that I started getting my dermatillomania under control.

'Even when I was having success with N-Dubz, I would have spells of picking and digging at my face when I felt under pressure or anxious.'