A cleaning expert on BBC Watchdog found that the Adelphi Hotel in Liverpool was the dirtiest they had tested.
The consumer rights show had hundreds of complaints from their viewers about the Britannia chain of hotels - who own the Adelphi.
After getting so many complaints they decided to send in a cleaning expert with a special device that could see exactly how dirty something was.
An item is swabbed, then the swab is put into the machine and a reading of between 50-100 is a cause for concern.
Delilah went to six Britannia hotels across the country including the Adelphi.
Delilah swabbed the bath tiles at the Ranelagh Street hotel and found they had a reading of 8081 , she said: "This is totally unacceptable, in excess of 8,000."
She then peered behind the loo and said: "The odor is atrocious, odor de urine."
And the bed wasn't a pretty sight either, with the mattress topper clearly stained.
Across all the hotels the readings weren't pretty - but Delilah did find better readings in other locations however she said she wouldn't stay in any of them.
Britannia told the show they had ten million guests each year, with a high proportion of returning customers.
It says it recognises the importance of clean bedrooms and while it doesn't accept that what we found is typical of its rooms it fully takes on board Delilah's comments.
An independent expert is set to do a review of its cleaning procedures to ensure it meets the highest standards.
