A PASSENGER on a Melbourne train was horrified to find a pile of steaming poo on a seat.

Aisha Dow, a reporter for Fairfax media, took a photo of the offending sight, writing: “There is a POO on my train. It smells.”

She then posted a video of a brave male passenger performing a public service by throwing tissues over the faeces but observed that “it still smells.”

The turd was left on one of the pull-down seats prioritised for disabled passengers on a train travelling from 17 kilometres southwest of the CBD.

Poo on a train update. Someone put tissues on it. It still smells. @theage @metrotrains pic.twitter.com/jpkxvwlF8Q — Aisha Dow (@aishamae) February 14, 2017

Melbourne’s Metro Trains Twitter account then stepped in, asking which carriage the poo was in so it could be cleaned.

“We are getting it checked, we have further reports that the train is from Laverton, can you confirm please?” tweeted the train service.

Metro Trains finished the conversation with “sorry about the discomfort caused”.

She did so, but said she had not recorded the carriage number.

We are used to seeing anti-social behaviour on public transport, from racist rants to feet on seats to toenail clippings. There are even social media accounts dedicated to naming and shaming Australia’s rudest passengers.

But this brings a whole new meaning to having a crap commute.

Do you know more about the mystery turd? Email news@news.com.au.