If you've stayed in certain luxury Melbourne hotels lately, you may well have lain on a mattress littered with pubic hair and dead skin cells. When you brushed your teeth, you could have rinsed your mouth in a basin laden with potentially deadly bacteria. And the toilet in your room would probably have been stained with other people's urine.

These are the shocking findings of an investigation into seven five- and four-star Melbourne hotels conducted by a former forensic police officer who now cleans up crime scenes. The Liquor Hospitality and Miscellaneous Union (LHMU) says the room attendants want to do their job properly, but instead of the 45 minutes required to clean a room to five-star standard, most are given only 15 minutes.

"Luxury hotels present themselves as a place of marble and chandeliers, and out the back we have third-world working conditions where people are just being forced to run through the rooms, spot clean, do the best they can and move on," LHMU Victorian secretary Jess Walsh told reporters on Tuesday.

"I think guests, when they go to a five-star hotel, they expect luxury and they expect a nice, clean room."

The union has approached the hotels and asked them to sign a charter of respect, which would include giving room cleaners adequate time to do their jobs.

So far, the hotels had refused to meet with the room attendants, Ms Walsh said.

"They have to cut corners or face losing their jobs," she said.

Ms Walsh said the union, which has not put the results of the BIO-CLEAN investigation to the hotels involved, said it would not rule out naming the offending establishments.

But it would not name names at this stage because the problem was industry-wide.

BIO-CLEAN managing director Peter Guerin said that during his investigation, conducted in May, he found mould, body fat and hair in showers.

All of the seven hotels tested had urine stains on or around the toilets.

"One particular hotel came back with positive results for pseudomonas (in the bathroom basin), which is a water-borne pathogen which can make you extremely sick and in some people with low immune systems can kill them.

"Now, if that's in your basin when you're brushing your teeth, the chances of transference is fairly high."

Mr Guerin said there was a lot of dust in the rooms, which could pose problems for asthmatics, and the mattresses were full of skin cells, hair and some were stained with semen.

Mr Guerin was a police officer for 30 years, including eight in forensic science crime scene investigation.

He now runs BIO-CLEAN, which is a trauma cleaning business. During his investigation, he measured the number of living cells on swabs taken from surfaces. Unacceptable levels of living cells were found on phones, door handles and television remote controls, Mr Guerin said.

A Tourism Victoria spokeswoman said the state offered an excellent range of luxury hotels that pride themselves on delivering a high standard of service, quality and cleanliness.

''Our accommodation facilities are utilised by international, interstate and Victorian travellers alike with room occupancy rates at above 60 per cent for medium to large hotels, motels and serviced apartments across our state,'' she said in a statement.