An angry air passenger has written an open letter to the woman who made her holiday journey a flight from hell.

Lau Munyee, 24, had paid around £320 for what she expected to be a “routine” Air Asia flight from Singapore to Sydney.

But she said it turned into a “once in a lifetime experience” for all the wrong reasons once the passenger sat behind her got comfortable.

“I am writing this letter to thank you personally,” Ms Lau wrote sarcastically.

“Despite my common economy seat, you offered me a full back massage by repeatedly kicking the back of chair.

A photo posted by iaremunyee. (@iaremunyee) on Apr 7, 2015 at 8:03pm PDT

“To date, I have yet to regain full mobility of the lower half of my body. But since I am single, I suppose I don’t have much use for it anyway.”

There was no need for in-flight entertainment, she wrote, because the woman was talking so loudly she “wished for a hearing impairment”.

“Also, could you tell me where you bought those obnoxious snacks?” Ms Lau asked, assuming that the “loud rustling and chewing” meant they must have been delicious.

She wrote: “At this point, I thought, “It can’t get any better than this.” But what I had meant as a rhetorical question, you took as a challenge.

“For immediately, my nose was assaulted by a putrid smell of death and decay.

“The stench was so strong that I turned to check if the old lady seated next to me was still breathing.”

For more pictures of me ruining the beautiful scenery in Sydney, Australia, subscribe to my April newsletter:http://goo.gl/UxOtmKp/s:There's a surprise video too! Posted by Mun Yee on Sunday, 26 April 2015

The woman had taken off her shoes and squeezed her sock-clad feet between Ms Lau’s seat and the plane window.

“It must have taken considerable effort – it was a small space but you stuck it as close to my face as you possibly could,” she wrote. “Your kindness moves me.”

Even the beauty of a sunrise seen from the sky could not distract Ms Lau from a smell she compared to the “anus of Satan”.

She claimed she considered using the oxygen mask above her seat but feared the budget airline would charge her extra.

“Did you know that you have made me a more religious person?” Ms Lau asked her mystery tormentor, named only by seat number 15A.

“I have said more prayers in that eight-hour flight than I have in my entire life.”

Adding that she needed at least ten sessions of therapy to get over the journey, Ms Lau signed off: “Insincerely yours, passenger 14A.”

Ms Lau, who works as a freelance writer in Malaysia, said she wrote the furious letter on an empty sick bag as the nightmare flight continued.

“I couldn't sleep a wink throughout the entire flight and had to find a means of distracting myself from the smell - short of jumping off the plane,” she told Daily Mail Australia.